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elide unused imports in ES6 emit

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This commit is contained in:
Vladimir Matveev 2016-04-07 12:55:49 -07:00
parent 5c6009ceae
commit cc0cb5851b
2 changed files with 67 additions and 4 deletions
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20
src/compiler/factory.ts
View File

@ -710,6 +710,26 @@ namespace ts {
return createVoid(createLiteral(0));
}
export function createImportDeclaration(importClause: ImportClause, moduleSpecifier?: Expression, location?: TextRange): ImportDeclaration {
const node = <ImportDeclaration>createNode(SyntaxKind.ImportDeclaration, location);
node.importClause = importClause;
node.moduleSpecifier = moduleSpecifier;
return node;
}
export function createImportClause(name: Identifier, namedBindings: NamedImportBindings, location?: TextRange): ImportClause {
const node = <ImportClause>createNode(SyntaxKind.ImportClause, location);
node.name = name;
node.namedBindings = namedBindings;
return node;
}
export function createNamedImports(elements: NodeArray<ImportSpecifier>, location?: TextRange): NamedImports {
const node = <NamedImports>createNode(SyntaxKind.NamedImports, location);
node.elements = elements;
return node;
}
export function createMemberAccessForPropertyName(target: Expression, memberName: PropertyName, location?: TextRange): MemberExpression {
if (isIdentifier(memberName)) {
return createPropertyAccess(target, getSynthesizedClone(memberName), location);

51
src/compiler/transformers/module/es6.ts
View File

@ -19,21 +19,64 @@ namespace ts {
return node;
}
function visitor(node: Node) {
function visitor(node: Node): VisitResult<Node> {
switch (node.kind) {
case SyntaxKind.ImportDeclaration:
return visitImportDeclaration(<ImportDeclaration>node);
case SyntaxKind.ImportClause:
return visitImportClause(<ImportClause>node);
case SyntaxKind.NamedImports:
case SyntaxKind.NamespaceImport:
return visitNamedBindings(<NamedImportBindings>node);
case SyntaxKind.ImportSpecifier:
return visitImportSpecifier(<ImportSpecifier>node);
}
return node;
}
function visitImportDeclaration(node: ImportDeclaration) {
if (node.importClause && !resolver.isReferencedAliasDeclaration(node.importClause, /*checkChildren*/ true)) {
return undefined;
if (node.importClause) {
const newImportClause = visitNode(node.importClause, visitor, isImportClause);
if (!newImportClause.name && !newImportClause.namedBindings) {
return undefined;
}
else if (newImportClause !== node.importClause) {
return createImportDeclaration(newImportClause, node.moduleSpecifier);
}
}
return node;
}
function visitImportClause(node: ImportClause): ImportClause {
let newDefaultImport = node.name;
if (!resolver.isReferencedAliasDeclaration(node)) {
newDefaultImport = undefined;
}
const newNamedBindings = visitNode(node.namedBindings, visitor, isNamedImportBindings, /*optional*/ true);
return newDefaultImport !== node.name || newNamedBindings !== node.namedBindings
? createImportClause(newDefaultImport, newNamedBindings)
: node;
}
function visitNamedBindings(node: NamedImportBindings): VisitResult<NamedImportBindings> {
if (node.kind === SyntaxKind.NamespaceImport) {
return resolver.isReferencedAliasDeclaration(node) ? node: undefined;
}
else {
const newNamedImportElements = visitNodes((<NamedImports>node).elements, visitor, isImportSpecifier);
if (!newNamedImportElements || newNamedImportElements.length == 0) {
return undefined;
}
if (newNamedImportElements === (<NamedImports>node).elements) {
return node;
}
return createNamedImports(newNamedImportElements);
}
}
function visitImportSpecifier(node: ImportSpecifier) {
return resolver.isReferencedAliasDeclaration(node) ? node : undefined;
}
}
}