mirror of
https://github.com/microsoft/TypeScript.git
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551 lines
34 KiB
TypeScript
551 lines
34 KiB
TypeScript
/* @internal */
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namespace ts.SignatureHelp {
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const enum InvocationKind { Call, TypeArgs, Contextual }
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interface CallInvocation { readonly kind: InvocationKind.Call; readonly node: CallLikeExpression; }
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interface TypeArgsInvocation { readonly kind: InvocationKind.TypeArgs; readonly called: Expression; }
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interface ContextualInvocation {
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readonly kind: InvocationKind.Contextual;
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readonly signature: Signature;
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readonly node: Node; // Just for enclosingDeclaration for printing types
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readonly symbol: Symbol;
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}
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type Invocation = CallInvocation | TypeArgsInvocation | ContextualInvocation;
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interface ArgumentListInfo {
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readonly isTypeParameterList: boolean;
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readonly invocation: Invocation;
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readonly argumentsSpan: TextSpan;
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readonly argumentIndex: number;
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/** argumentCount is the *apparent* number of arguments. */
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readonly argumentCount: number;
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}
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export function getSignatureHelpItems(program: Program, sourceFile: SourceFile, position: number, triggerReason: SignatureHelpTriggerReason | undefined, cancellationToken: CancellationToken): SignatureHelpItems | undefined {
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const typeChecker = program.getTypeChecker();
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// Decide whether to show signature help
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const startingToken = findTokenOnLeftOfPosition(sourceFile, position);
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if (!startingToken) {
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// We are at the beginning of the file
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return undefined;
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}
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// Only need to be careful if the user typed a character and signature help wasn't showing.
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const onlyUseSyntacticOwners = !!triggerReason && triggerReason.kind === "characterTyped";
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// Bail out quickly in the middle of a string or comment, don't provide signature help unless the user explicitly requested it.
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if (onlyUseSyntacticOwners && (isInString(sourceFile, position, startingToken) || isInComment(sourceFile, position))) {
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return undefined;
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}
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const argumentInfo = getContainingArgumentInfo(startingToken, position, sourceFile, typeChecker);
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if (!argumentInfo) return undefined;
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cancellationToken.throwIfCancellationRequested();
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// Extra syntactic and semantic filtering of signature help
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const candidateInfo = getCandidateInfo(argumentInfo, typeChecker, sourceFile, startingToken, onlyUseSyntacticOwners);
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cancellationToken.throwIfCancellationRequested();
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if (!candidateInfo) {
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// We didn't have any sig help items produced by the TS compiler. If this is a JS
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// file, then see if we can figure out anything better.
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return isSourceFileJavaScript(sourceFile) ? createJavaScriptSignatureHelpItems(argumentInfo, program, cancellationToken) : undefined;
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}
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return typeChecker.runWithCancellationToken(cancellationToken, typeChecker => createSignatureHelpItems(candidateInfo.candidates, candidateInfo.resolvedSignature, argumentInfo, sourceFile, typeChecker));
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}
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interface CandidateInfo { readonly candidates: ReadonlyArray<Signature>; readonly resolvedSignature: Signature; }
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function getCandidateInfo({ invocation, argumentCount }: ArgumentListInfo, checker: TypeChecker, sourceFile: SourceFile, startingToken: Node, onlyUseSyntacticOwners: boolean): CandidateInfo | undefined {
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switch (invocation.kind) {
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case InvocationKind.Call: {
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if (onlyUseSyntacticOwners && !isSyntacticOwner(startingToken, invocation.node, sourceFile)) {
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return undefined;
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}
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const candidates: Signature[] = [];
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const resolvedSignature = checker.getResolvedSignatureForSignatureHelp(invocation.node, candidates, argumentCount)!; // TODO: GH#18217
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return candidates.length === 0 ? undefined : { candidates, resolvedSignature };
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}
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case InvocationKind.TypeArgs: {
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if (onlyUseSyntacticOwners && !lessThanFollowsCalledExpression(startingToken, sourceFile, invocation.called)) {
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return undefined;
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}
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const candidates = getPossibleGenericSignatures(invocation.called, argumentCount, checker);
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return candidates.length === 0 ? undefined : { candidates, resolvedSignature: first(candidates) };
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}
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case InvocationKind.Contextual:
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return { candidates: [invocation.signature], resolvedSignature: invocation.signature };
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default:
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return Debug.assertNever(invocation);
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}
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}
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function isSyntacticOwner(startingToken: Node, node: CallLikeExpression, sourceFile: SourceFile): boolean {
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if (!isCallOrNewExpression(node)) return false;
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const invocationChildren = node.getChildren(sourceFile);
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switch (startingToken.kind) {
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case SyntaxKind.OpenParenToken:
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return contains(invocationChildren, startingToken);
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case SyntaxKind.CommaToken: {
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const containingList = findContainingList(startingToken);
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return !!containingList && contains(invocationChildren, containingList);
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}
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case SyntaxKind.LessThanToken:
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return lessThanFollowsCalledExpression(startingToken, sourceFile, node.expression);
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default:
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return false;
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}
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}
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function createJavaScriptSignatureHelpItems(argumentInfo: ArgumentListInfo, program: Program, cancellationToken: CancellationToken): SignatureHelpItems | undefined {
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if (argumentInfo.invocation.kind === InvocationKind.Contextual) return undefined;
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// See if we can find some symbol with the call expression name that has call signatures.
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const expression = getExpressionFromInvocation(argumentInfo.invocation);
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const name = isIdentifier(expression) ? expression.text : isPropertyAccessExpression(expression) ? expression.name.text : undefined;
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const typeChecker = program.getTypeChecker();
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return name === undefined ? undefined : firstDefined(program.getSourceFiles(), sourceFile =>
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firstDefined(sourceFile.getNamedDeclarations().get(name), declaration => {
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const type = declaration.symbol && typeChecker.getTypeOfSymbolAtLocation(declaration.symbol, declaration);
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const callSignatures = type && type.getCallSignatures();
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if (callSignatures && callSignatures.length) {
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return typeChecker.runWithCancellationToken(cancellationToken, typeChecker => createSignatureHelpItems(callSignatures, callSignatures[0], argumentInfo, sourceFile, typeChecker));
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}
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}));
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}
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function lessThanFollowsCalledExpression(startingToken: Node, sourceFile: SourceFile, calledExpression: Expression) {
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const precedingToken = Debug.assertDefined(
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findPrecedingToken(startingToken.getFullStart(), sourceFile, startingToken.parent, /*excludeJsdoc*/ true)
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);
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return rangeContainsRange(calledExpression, precedingToken);
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}
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export interface ArgumentInfoForCompletions {
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readonly invocation: CallLikeExpression;
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readonly argumentIndex: number;
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readonly argumentCount: number;
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}
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export function getArgumentInfoForCompletions(node: Node, position: number, sourceFile: SourceFile): ArgumentInfoForCompletions | undefined {
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const info = getImmediatelyContainingArgumentInfo(node, position, sourceFile);
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return !info || info.isTypeParameterList || info.invocation.kind !== InvocationKind.Call ? undefined
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: { invocation: info.invocation.node, argumentCount: info.argumentCount, argumentIndex: info.argumentIndex };
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}
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function getArgumentOrParameterListInfo(node: Node, sourceFile: SourceFile): { readonly list: Node, readonly argumentIndex: number, readonly argumentCount: number, readonly argumentsSpan: TextSpan } | undefined {
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const info = getArgumentOrParameterListAndIndex(node, sourceFile);
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if (!info) return undefined;
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const { list, argumentIndex } = info;
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const argumentCount = getArgumentCount(list);
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if (argumentIndex !== 0) {
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Debug.assertLessThan(argumentIndex, argumentCount);
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}
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const argumentsSpan = getApplicableSpanForArguments(list, sourceFile);
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return { list, argumentIndex, argumentCount, argumentsSpan };
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}
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function getArgumentOrParameterListAndIndex(node: Node, sourceFile: SourceFile): { readonly list: Node, readonly argumentIndex: number } | undefined {
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if (node.kind === SyntaxKind.LessThanToken || node.kind === SyntaxKind.OpenParenToken) {
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// Find the list that starts right *after* the < or ( token.
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// If the user has just opened a list, consider this item 0.
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return { list: getChildListThatStartsWithOpenerToken(node.parent, node, sourceFile), argumentIndex: 0 };
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}
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else {
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// findListItemInfo can return undefined if we are not in parent's argument list
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// or type argument list. This includes cases where the cursor is:
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// - To the right of the closing parenthesis, non-substitution template, or template tail.
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// - Between the type arguments and the arguments (greater than token)
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// - On the target of the call (parent.func)
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// - On the 'new' keyword in a 'new' expression
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const list = findContainingList(node);
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return list && { list, argumentIndex: getArgumentIndex(list, node) };
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}
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}
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/**
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* Returns relevant information for the argument list and the current argument if we are
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* in the argument of an invocation; returns undefined otherwise.
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*/
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function getImmediatelyContainingArgumentInfo(node: Node, position: number, sourceFile: SourceFile): ArgumentListInfo | undefined {
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const { parent } = node;
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if (isCallOrNewExpression(parent)) {
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const invocation = parent;
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// There are 3 cases to handle:
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// 1. The token introduces a list, and should begin a signature help session
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// 2. The token is either not associated with a list, or ends a list, so the session should end
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// 3. The token is buried inside a list, and should give signature help
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//
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// The following are examples of each:
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//
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// Case 1:
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// foo<#T, U>(#a, b) -> The token introduces a list, and should begin a signature help session
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// Case 2:
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// fo#o<T, U>#(a, b)# -> The token is either not associated with a list, or ends a list, so the session should end
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// Case 3:
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// foo<T#, U#>(a#, #b#) -> The token is buried inside a list, and should give signature help
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// Find out if 'node' is an argument, a type argument, or neither
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const info = getArgumentOrParameterListInfo(node, sourceFile);
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if (!info) return undefined;
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const { list, argumentIndex, argumentCount, argumentsSpan } = info;
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const isTypeParameterList = !!parent.typeArguments && parent.typeArguments.pos === list.pos;
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return { isTypeParameterList, invocation: { kind: InvocationKind.Call, node: invocation }, argumentsSpan, argumentIndex, argumentCount };
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}
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else if (isNoSubstitutionTemplateLiteral(node) && isTaggedTemplateExpression(parent)) {
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// Check if we're actually inside the template;
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// otherwise we'll fall out and return undefined.
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if (isInsideTemplateLiteral(node, position, sourceFile)) {
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return getArgumentListInfoForTemplate(parent, /*argumentIndex*/ 0, sourceFile);
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}
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return undefined;
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}
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else if (isTemplateHead(node) && parent.parent.kind === SyntaxKind.TaggedTemplateExpression) {
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const templateExpression = <TemplateExpression>parent;
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const tagExpression = <TaggedTemplateExpression>templateExpression.parent;
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Debug.assert(templateExpression.kind === SyntaxKind.TemplateExpression);
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const argumentIndex = isInsideTemplateLiteral(node, position, sourceFile) ? 0 : 1;
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return getArgumentListInfoForTemplate(tagExpression, argumentIndex, sourceFile);
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}
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else if (isTemplateSpan(parent) && isTaggedTemplateExpression(parent.parent.parent)) {
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const templateSpan = parent;
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const tagExpression = parent.parent.parent;
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// If we're just after a template tail, don't show signature help.
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if (isTemplateTail(node) && !isInsideTemplateLiteral(node, position, sourceFile)) {
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return undefined;
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}
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const spanIndex = templateSpan.parent.templateSpans.indexOf(templateSpan);
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const argumentIndex = getArgumentIndexForTemplatePiece(spanIndex, node, position, sourceFile);
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return getArgumentListInfoForTemplate(tagExpression, argumentIndex, sourceFile);
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}
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else if (isJsxOpeningLikeElement(parent)) {
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// Provide a signature help for JSX opening element or JSX self-closing element.
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// This is not guarantee that JSX tag-name is resolved into stateless function component. (that is done in "getSignatureHelpItems")
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// i.e
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// export function MainButton(props: ButtonProps, context: any): JSX.Element { ... }
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// <MainButton /*signatureHelp*/
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const attributeSpanStart = parent.attributes.pos;
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const attributeSpanEnd = skipTrivia(sourceFile.text, parent.attributes.end, /*stopAfterLineBreak*/ false);
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return {
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isTypeParameterList: false,
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invocation: { kind: InvocationKind.Call, node: parent },
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argumentsSpan: createTextSpan(attributeSpanStart, attributeSpanEnd - attributeSpanStart),
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argumentIndex: 0,
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argumentCount: 1
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};
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}
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else {
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const typeArgInfo = getPossibleTypeArgumentsInfo(node, sourceFile);
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if (typeArgInfo) {
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const { called, nTypeArguments } = typeArgInfo;
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const invocation: Invocation = { kind: InvocationKind.TypeArgs, called };
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const argumentsSpan = createTextSpanFromBounds(called.getStart(sourceFile), node.end);
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return { isTypeParameterList: true, invocation, argumentsSpan, argumentIndex: nTypeArguments, argumentCount: nTypeArguments + 1 };
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}
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return undefined;
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}
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}
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function getImmediatelyContainingArgumentOrContextualParameterInfo(node: Node, position: number, sourceFile: SourceFile, checker: TypeChecker): ArgumentListInfo | undefined {
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return tryGetParameterInfo(node, position, sourceFile, checker) || getImmediatelyContainingArgumentInfo(node, position, sourceFile);
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}
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function getHighestBinary(b: BinaryExpression): BinaryExpression {
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return isBinaryExpression(b.parent) ? getHighestBinary(b.parent) : b;
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}
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function countBinaryExpressionParameters(b: BinaryExpression): number {
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return isBinaryExpression(b.left) ? countBinaryExpressionParameters(b.left) + 1 : 2;
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}
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function tryGetParameterInfo(startingToken: Node, _position: number, sourceFile: SourceFile, checker: TypeChecker): ArgumentListInfo | undefined {
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const info = getContextualSignatureLocationInfo(startingToken, sourceFile, checker);
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if (!info) return undefined;
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const { contextualType, argumentIndex, argumentCount, argumentsSpan } = info;
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const signatures = contextualType.getCallSignatures();
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if (signatures.length !== 1) return undefined;
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const invocation: ContextualInvocation = { kind: InvocationKind.Contextual, signature: first(signatures), node: startingToken, symbol: chooseBetterSymbol(contextualType.symbol) };
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return { isTypeParameterList: false, invocation, argumentsSpan, argumentIndex, argumentCount };
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}
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interface ContextualSignatureLocationInfo {readonly contextualType: Type; readonly argumentIndex: number; readonly argumentCount: number; readonly argumentsSpan: TextSpan; }
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function getContextualSignatureLocationInfo(startingToken: Node, sourceFile: SourceFile, checker: TypeChecker): ContextualSignatureLocationInfo | undefined {
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if (startingToken.kind !== SyntaxKind.OpenParenToken && startingToken.kind !== SyntaxKind.CommaToken) return undefined;
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const { parent } = startingToken;
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switch (parent.kind) {
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case SyntaxKind.ParenthesizedExpression:
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case SyntaxKind.MethodDeclaration:
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case SyntaxKind.FunctionExpression:
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case SyntaxKind.ArrowFunction:
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const info = getArgumentOrParameterListInfo(startingToken, sourceFile);
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if (!info) return undefined;
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const { argumentIndex, argumentCount, argumentsSpan } = info;
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const contextualType = isMethodDeclaration(parent) ? checker.getContextualTypeForObjectLiteralElement(parent) : checker.getContextualType(parent as ParenthesizedExpression | FunctionExpression | ArrowFunction);
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return contextualType && { contextualType, argumentIndex, argumentCount, argumentsSpan };
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case SyntaxKind.BinaryExpression: {
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const highestBinary = getHighestBinary(parent as BinaryExpression);
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const contextualType = checker.getContextualType(highestBinary);
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const argumentIndex = startingToken.kind === SyntaxKind.OpenParenToken ? 0 : countBinaryExpressionParameters(parent as BinaryExpression) - 1;
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const argumentCount = countBinaryExpressionParameters(highestBinary);
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return contextualType && { contextualType, argumentIndex, argumentCount, argumentsSpan: createTextSpanFromNode(parent) };
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}
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default:
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return undefined;
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}
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}
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// The type of a function type node has a symbol at that node, but it's better to use the symbol for a parameter or type alias.
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function chooseBetterSymbol(s: Symbol): Symbol {
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return s.name === InternalSymbolName.Type
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? firstDefined(s.declarations, d => isFunctionTypeNode(d) ? d.parent.symbol : undefined) || s
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: s;
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}
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function getArgumentIndex(argumentsList: Node, node: Node) {
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// The list we got back can include commas. In the presence of errors it may
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// also just have nodes without commas. For example "Foo(a b c)" will have 3
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// args without commas. We want to find what index we're at. So we count
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// forward until we hit ourselves, only incrementing the index if it isn't a
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// comma.
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//
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// Note: the subtlety around trailing commas (in getArgumentCount) does not apply
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// here. That's because we're only walking forward until we hit the node we're
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// on. In that case, even if we're after the trailing comma, we'll still see
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// that trailing comma in the list, and we'll have generated the appropriate
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// arg index.
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let argumentIndex = 0;
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for (const child of argumentsList.getChildren()) {
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if (child === node) {
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break;
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}
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if (child.kind !== SyntaxKind.CommaToken) {
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argumentIndex++;
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}
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}
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return argumentIndex;
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}
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function getArgumentCount(argumentsList: Node) {
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// The argument count for a list is normally the number of non-comma children it has.
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// For example, if you have "Foo(a,b)" then there will be three children of the arg
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// list 'a' '<comma>' 'b'. So, in this case the arg count will be 2. However, there
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// is a small subtlety. If you have "Foo(a,)", then the child list will just have
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// 'a' '<comma>'. So, in the case where the last child is a comma, we increase the
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// arg count by one to compensate.
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//
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// Note: this subtlety only applies to the last comma. If you had "Foo(a,," then
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// we'll have: 'a' '<comma>' '<missing>'
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// That will give us 2 non-commas. We then add one for the last comma, giving us an
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// arg count of 3.
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const listChildren = argumentsList.getChildren();
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let argumentCount = countWhere(listChildren, arg => arg.kind !== SyntaxKind.CommaToken);
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if (listChildren.length > 0 && last(listChildren).kind === SyntaxKind.CommaToken) {
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argumentCount++;
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}
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return argumentCount;
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}
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// spanIndex is either the index for a given template span.
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// This does not give appropriate results for a NoSubstitutionTemplateLiteral
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function getArgumentIndexForTemplatePiece(spanIndex: number, node: Node, position: number, sourceFile: SourceFile): number {
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// Because the TemplateStringsArray is the first argument, we have to offset each substitution expression by 1.
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// There are three cases we can encounter:
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// 1. We are precisely in the template literal (argIndex = 0).
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// 2. We are in or to the right of the substitution expression (argIndex = spanIndex + 1).
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// 3. We are directly to the right of the template literal, but because we look for the token on the left,
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// not enough to put us in the substitution expression; we should consider ourselves part of
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// the *next* span's expression by offsetting the index (argIndex = (spanIndex + 1) + 1).
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//
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// tslint:disable no-double-space
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// Example: f `# abcd $#{# 1 + 1# }# efghi ${ #"#hello"# } # `
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// ^ ^ ^ ^ ^ ^ ^ ^ ^
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// Case: 1 1 3 2 1 3 2 2 1
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// tslint:enable no-double-space
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Debug.assert(position >= node.getStart(), "Assumed 'position' could not occur before node.");
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if (isTemplateLiteralToken(node)) {
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if (isInsideTemplateLiteral(node, position, sourceFile)) {
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return 0;
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}
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return spanIndex + 2;
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}
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return spanIndex + 1;
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}
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function getArgumentListInfoForTemplate(tagExpression: TaggedTemplateExpression, argumentIndex: number, sourceFile: SourceFile): ArgumentListInfo {
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// argumentCount is either 1 or (numSpans + 1) to account for the template strings array argument.
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const argumentCount = isNoSubstitutionTemplateLiteral(tagExpression.template) ? 1 : tagExpression.template.templateSpans.length + 1;
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if (argumentIndex !== 0) {
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Debug.assertLessThan(argumentIndex, argumentCount);
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}
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return {
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isTypeParameterList: false,
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invocation: { kind: InvocationKind.Call, node: tagExpression },
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argumentsSpan: getApplicableSpanForTaggedTemplate(tagExpression, sourceFile),
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argumentIndex,
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argumentCount
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};
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}
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function getApplicableSpanForArguments(argumentsList: Node, sourceFile: SourceFile): TextSpan {
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// We use full start and skip trivia on the end because we want to include trivia on
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// both sides. For example,
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//
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// foo( /*comment */ a, b, c /*comment*/ )
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// | |
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//
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// The applicable span is from the first bar to the second bar (inclusive,
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// but not including parentheses)
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const applicableSpanStart = argumentsList.getFullStart();
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const applicableSpanEnd = skipTrivia(sourceFile.text, argumentsList.getEnd(), /*stopAfterLineBreak*/ false);
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return createTextSpan(applicableSpanStart, applicableSpanEnd - applicableSpanStart);
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}
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function getApplicableSpanForTaggedTemplate(taggedTemplate: TaggedTemplateExpression, sourceFile: SourceFile): TextSpan {
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const template = taggedTemplate.template;
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const applicableSpanStart = template.getStart();
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let applicableSpanEnd = template.getEnd();
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|
|
|
// We need to adjust the end position for the case where the template does not have a tail.
|
|
// Otherwise, we will not show signature help past the expression.
|
|
// For example,
|
|
//
|
|
// ` ${ 1 + 1 foo(10)
|
|
// | |
|
|
// This is because a Missing node has no width. However, what we actually want is to include trivia
|
|
// leading up to the next token in case the user is about to type in a TemplateMiddle or TemplateTail.
|
|
if (template.kind === SyntaxKind.TemplateExpression) {
|
|
const lastSpan = last(template.templateSpans);
|
|
if (lastSpan.literal.getFullWidth() === 0) {
|
|
applicableSpanEnd = skipTrivia(sourceFile.text, applicableSpanEnd, /*stopAfterLineBreak*/ false);
|
|
}
|
|
}
|
|
|
|
return createTextSpan(applicableSpanStart, applicableSpanEnd - applicableSpanStart);
|
|
}
|
|
|
|
function getContainingArgumentInfo(node: Node, position: number, sourceFile: SourceFile, checker: TypeChecker): ArgumentListInfo | undefined {
|
|
for (let n = node; !isBlock(n) && !isSourceFile(n); n = n.parent) {
|
|
// If the node is not a subspan of its parent, this is a big problem.
|
|
// There have been crashes that might be caused by this violation.
|
|
Debug.assert(rangeContainsRange(n.parent, n), "Not a subspan", () => `Child: ${Debug.showSyntaxKind(n)}, parent: ${Debug.showSyntaxKind(n.parent)}`);
|
|
const argumentInfo = getImmediatelyContainingArgumentOrContextualParameterInfo(n, position, sourceFile, checker);
|
|
if (argumentInfo) {
|
|
return argumentInfo;
|
|
}
|
|
}
|
|
return undefined;
|
|
}
|
|
|
|
function getChildListThatStartsWithOpenerToken(parent: Node, openerToken: Node, sourceFile: SourceFile): Node {
|
|
const children = parent.getChildren(sourceFile);
|
|
const indexOfOpenerToken = children.indexOf(openerToken);
|
|
Debug.assert(indexOfOpenerToken >= 0 && children.length > indexOfOpenerToken + 1);
|
|
return children[indexOfOpenerToken + 1];
|
|
}
|
|
|
|
function getExpressionFromInvocation(invocation: CallInvocation | TypeArgsInvocation): Expression {
|
|
return invocation.kind === InvocationKind.Call ? getInvokedExpression(invocation.node) : invocation.called;
|
|
}
|
|
|
|
const signatureHelpNodeBuilderFlags = NodeBuilderFlags.OmitParameterModifiers | NodeBuilderFlags.IgnoreErrors | NodeBuilderFlags.UseAliasDefinedOutsideCurrentScope;
|
|
function createSignatureHelpItems(
|
|
candidates: ReadonlyArray<Signature>,
|
|
resolvedSignature: Signature,
|
|
{ isTypeParameterList, argumentCount, argumentsSpan: applicableSpan, invocation, argumentIndex }: ArgumentListInfo,
|
|
sourceFile: SourceFile,
|
|
typeChecker: TypeChecker,
|
|
): SignatureHelpItems {
|
|
const enclosingDeclaration = invocation.kind === InvocationKind.Call ? invocation.node : invocation.kind === InvocationKind.TypeArgs ? invocation.called : invocation.node;
|
|
const callTargetSymbol = invocation.kind === InvocationKind.Contextual ? invocation.symbol : typeChecker.getSymbolAtLocation(getExpressionFromInvocation(invocation));
|
|
const callTargetDisplayParts = callTargetSymbol ? symbolToDisplayParts(typeChecker, callTargetSymbol, /*enclosingDeclaration*/ undefined, /*meaning*/ undefined) : emptyArray;
|
|
const items = candidates.map(candidateSignature => getSignatureHelpItem(candidateSignature, callTargetDisplayParts, isTypeParameterList, typeChecker, enclosingDeclaration, sourceFile));
|
|
|
|
if (argumentIndex !== 0) {
|
|
Debug.assertLessThan(argumentIndex, argumentCount);
|
|
}
|
|
|
|
const selectedItemIndex = candidates.indexOf(resolvedSignature);
|
|
Debug.assert(selectedItemIndex !== -1); // If candidates is non-empty it should always include bestSignature. We check for an empty candidates before calling this function.
|
|
|
|
return { items, applicableSpan, selectedItemIndex, argumentIndex, argumentCount };
|
|
}
|
|
|
|
function getSignatureHelpItem(candidateSignature: Signature, callTargetDisplayParts: ReadonlyArray<SymbolDisplayPart>, isTypeParameterList: boolean, checker: TypeChecker, enclosingDeclaration: Node, sourceFile: SourceFile): SignatureHelpItem {
|
|
const { isVariadic, parameters, prefix, suffix } = (isTypeParameterList ? itemInfoForTypeParameters : itemInfoForParameters)(candidateSignature, checker, enclosingDeclaration, sourceFile);
|
|
const prefixDisplayParts = [...callTargetDisplayParts, ...prefix];
|
|
const suffixDisplayParts = [...suffix, ...returnTypeToDisplayParts(candidateSignature, enclosingDeclaration, checker)];
|
|
const separatorDisplayParts = [punctuationPart(SyntaxKind.CommaToken), spacePart()];
|
|
const documentation = candidateSignature.getDocumentationComment(checker);
|
|
const tags = candidateSignature.getJsDocTags();
|
|
return { isVariadic, prefixDisplayParts, suffixDisplayParts, separatorDisplayParts, parameters, documentation, tags };
|
|
}
|
|
|
|
function returnTypeToDisplayParts(candidateSignature: Signature, enclosingDeclaration: Node, checker: TypeChecker): ReadonlyArray<SymbolDisplayPart> {
|
|
return mapToDisplayParts(writer => {
|
|
writer.writePunctuation(":");
|
|
writer.writeSpace(" ");
|
|
const predicate = checker.getTypePredicateOfSignature(candidateSignature);
|
|
if (predicate) {
|
|
checker.writeTypePredicate(predicate, enclosingDeclaration, /*flags*/ undefined, writer);
|
|
}
|
|
else {
|
|
checker.writeType(checker.getReturnTypeOfSignature(candidateSignature), enclosingDeclaration, /*flags*/ undefined, writer);
|
|
}
|
|
});
|
|
}
|
|
|
|
interface SignatureHelpItemInfo { readonly isVariadic: boolean; readonly parameters: SignatureHelpParameter[]; readonly prefix: ReadonlyArray<SymbolDisplayPart>; readonly suffix: ReadonlyArray<SymbolDisplayPart>; }
|
|
|
|
function itemInfoForTypeParameters(candidateSignature: Signature, checker: TypeChecker, enclosingDeclaration: Node, sourceFile: SourceFile): SignatureHelpItemInfo {
|
|
const typeParameters = (candidateSignature.target || candidateSignature).typeParameters;
|
|
const printer = createPrinter({ removeComments: true });
|
|
const parameters = (typeParameters || emptyArray).map(t => createSignatureHelpParameterForTypeParameter(t, checker, enclosingDeclaration, sourceFile, printer));
|
|
const parameterParts = mapToDisplayParts(writer => {
|
|
const thisParameter = candidateSignature.thisParameter ? [checker.symbolToParameterDeclaration(candidateSignature.thisParameter, enclosingDeclaration, signatureHelpNodeBuilderFlags)!] : [];
|
|
const params = createNodeArray([...thisParameter, ...candidateSignature.parameters.map(param => checker.symbolToParameterDeclaration(param, enclosingDeclaration, signatureHelpNodeBuilderFlags)!)]);
|
|
printer.writeList(ListFormat.CallExpressionArguments, params, sourceFile, writer);
|
|
});
|
|
return { isVariadic: false, parameters, prefix: [punctuationPart(SyntaxKind.LessThanToken)], suffix: [punctuationPart(SyntaxKind.GreaterThanToken), ...parameterParts] };
|
|
}
|
|
|
|
function itemInfoForParameters(candidateSignature: Signature, checker: TypeChecker, enclosingDeclaration: Node, sourceFile: SourceFile): SignatureHelpItemInfo {
|
|
const isVariadic = candidateSignature.hasRestParameter;
|
|
const printer = createPrinter({ removeComments: true });
|
|
const typeParameterParts = mapToDisplayParts(writer => {
|
|
if (candidateSignature.typeParameters && candidateSignature.typeParameters.length) {
|
|
const args = createNodeArray(candidateSignature.typeParameters.map(p => checker.typeParameterToDeclaration(p, enclosingDeclaration)!));
|
|
printer.writeList(ListFormat.TypeParameters, args, sourceFile, writer);
|
|
}
|
|
});
|
|
const parameters = candidateSignature.parameters.map(p => createSignatureHelpParameterForParameter(p, checker, enclosingDeclaration, sourceFile, printer));
|
|
return { isVariadic, parameters, prefix: [...typeParameterParts, punctuationPart(SyntaxKind.OpenParenToken)], suffix: [punctuationPart(SyntaxKind.CloseParenToken)] };
|
|
}
|
|
|
|
function createSignatureHelpParameterForParameter(parameter: Symbol, checker: TypeChecker, enclosingDeclaration: Node, sourceFile: SourceFile, printer: Printer): SignatureHelpParameter {
|
|
const displayParts = mapToDisplayParts(writer => {
|
|
const param = checker.symbolToParameterDeclaration(parameter, enclosingDeclaration, signatureHelpNodeBuilderFlags)!;
|
|
printer.writeNode(EmitHint.Unspecified, param, sourceFile, writer);
|
|
});
|
|
const isOptional = checker.isOptionalParameter(<ParameterDeclaration>parameter.valueDeclaration);
|
|
return { name: parameter.name, documentation: parameter.getDocumentationComment(checker), displayParts, isOptional };
|
|
}
|
|
|
|
function createSignatureHelpParameterForTypeParameter(typeParameter: TypeParameter, checker: TypeChecker, enclosingDeclaration: Node, sourceFile: SourceFile, printer: Printer): SignatureHelpParameter {
|
|
const displayParts = mapToDisplayParts(writer => {
|
|
const param = checker.typeParameterToDeclaration(typeParameter, enclosingDeclaration)!;
|
|
printer.writeNode(EmitHint.Unspecified, param, sourceFile, writer);
|
|
});
|
|
return { name: typeParameter.symbol.name, documentation: emptyArray, displayParts, isOptional: false };
|
|
}
|
|
}
|