Treat multiple prototype property assignments as union property declarations

RyanCavanaugh · RyanCavanaugh · commit a4c6f666862d · 2016-02-01T20:59:37.000-08:00
diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
@@ -2827,7 +2827,7 @@ namespace ts {
                 }
                 // Handle module.exports = expr
                 if (declaration.kind === SyntaxKind.BinaryExpression) {
-                    return links.type = checkExpression((<BinaryExpression>declaration).right);
+                    return links.type = getUnionType(map(symbol.declarations, (decl: BinaryExpression) => checkExpressionCached(decl.right)));
                 }
                 if (declaration.kind === SyntaxKind.PropertyAccessExpression) {
                     // Declarations only exist for property access expressions for certain
diff --git a/tests/cases/fourslash/getJavaScriptSemanticDiagnostics24.ts b/tests/cases/fourslash/getJavaScriptSemanticDiagnostics24.ts
@@ -0,0 +1,16 @@
+/// <reference path="fourslash.ts" />
+
+// @allowJs: true
+// @Filename: a.js
+//// function Person(age) {
+////     if (age >= 18) {
+////         this.canVote = true;
+////     } else {
+////         this.canVote = 23;
+////     }
+//// }
+//// let x = new Person(100);
+//// x.canVote/**/;
+
+goTo.marker();
+verify.quickInfoIs('(property) Person.canVote: boolean | number');

Original file line number	Diff line number	Diff line change
`@@ -2827,7 +2827,7 @@ namespace ts {`
`2827`	`2827`	`}`
`2828`	`2828`	`// Handle module.exports = expr`
`2829`	`2829`	`if (declaration.kind === SyntaxKind.BinaryExpression) {`
`2830`		`- return links.type = checkExpression((<BinaryExpression>declaration).right);`
	`2830`	`+ return links.type = getUnionType(map(symbol.declarations, (decl: BinaryExpression) => checkExpressionCached(decl.right)));`
`2831`	`2831`	`}`
`2832`	`2832`	`if (declaration.kind === SyntaxKind.PropertyAccessExpression) {`
`2833`	`2833`	`// Declarations only exist for property access expressions for certain`