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Merge pull request #1058 from Microsoft/contextualUnionTypeConformance

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Contextual union type conformance test cases and Fix for contextual union signature
This commit is contained in:
Sheetal Nandi
2014-11-06 16:25:40 -08:00
parent 727f36ad02 a5cea935af
commit 9e2eb3bc03
13 changed files with 1618 additions and 6 deletions
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35
src/compiler/checker.ts
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@@ -4890,8 +4890,9 @@ module ts {
// Return the contextual signature for a given expression node. A contextual type provides a
// contextual signature if it has a single call signature and if that call signature is non-generic.
// If the contextual type is a union type and each constituent type that has a contextual signature
// provides the same contextual signature, then the union type provides that contextual signature.
// If the contextual type is a union type, get the signature from each type possible and if they are
// all identical ignoring their return type, the result is same signature but with return type as
// union type of return types from these signatures
function getContextualSignature(node: Expression): Signature {
var type = getContextualType(node);
if (!type) {
@@ -4900,19 +4901,41 @@ module ts {
if (!(type.flags & TypeFlags.Union)) {
return getNonGenericSignature(type);
}
var result: Signature;
var signatureList: Signature[];
var types = (<UnionType>type).types;
for (var i = 0; i < types.length; i++) {
// The signature set of all constituent type with call signatures should match
// So number of signatures allowed is either 0 or 1
if (signatureList &&
getSignaturesOfObjectOrUnionType(types[i], SignatureKind.Call).length > 1) {
return undefined;
}
var signature = getNonGenericSignature(types[i]);
if (signature) {
if (!result) {
result = signature;
if (!signatureList) {
// This signature will contribute to contextual union signature
signatureList = [signature];
}
else if (!compareSignatures(result, signature, /*compareReturnTypes*/ true, compareTypes)) {
else if (!compareSignatures(signatureList[0], signature, /*compareReturnTypes*/ false, compareTypes)) {
// Signatures arent identical, do not use
return undefined;
}
else {
// Use this signature for contextual union signature
signatureList.push(signature);
}
}
}
// Result is union of signatures collected (return type is union of return types of this signature set)
var result: Signature;
if (signatureList) {
result = cloneSignature(signatureList[0]);
// Clear resolved return type we possibly got from cloneSignature
result.resolvedReturnType = undefined;
result.unionSignatures = signatureList;
}
return result;
}