factory: correctly parenthesize conditional head (microsoft#34227)

ajafff · RyanCavanaugh · commit 178417f431a4 · 2019-10-16T10:41:52.000-07:00
Fixes: microsoft#34109
diff --git a/src/compiler/factory.ts b/src/compiler/factory.ts
@@ -4739,7 +4739,7 @@ namespace ts {
         const conditionalPrecedence = getOperatorPrecedence(SyntaxKind.ConditionalExpression, SyntaxKind.QuestionToken);
         const emittedCondition = skipPartiallyEmittedExpressions(condition);
         const conditionPrecedence = getExpressionPrecedence(emittedCondition);
-        if (compareValues(conditionPrecedence, conditionalPrecedence) === Comparison.LessThan) {
+        if (compareValues(conditionPrecedence, conditionalPrecedence) !== Comparison.GreaterThan) {
             return createParen(condition);
         }
         return condition;
diff --git a/tests/baselines/reference/propertyAccessChain.js b/tests/baselines/reference/propertyAccessChain.js
@@ -16,14 +16,19 @@ o5.b?.().c.d?.e;
 
 // GH#33744
 declare const o6: <T>() => undefined | ({ x: number });
-o6<number>()?.x;
+o6<number>()?.x;
+
+// GH#34109
+o1?.b ? 1 : 0;
 
 //// [propertyAccessChain.js]
 "use strict";
-var _a, _b, _c, _d, _e, _f, _g, _h, _j;
+var _a, _b, _c, _d, _e, _f, _g, _h, _j, _k;
 (_a = o1) === null || _a === void 0 ? void 0 : _a.b;
 (_b = o2) === null || _b === void 0 ? void 0 : _b.b.c;
 (_c = o3.b) === null || _c === void 0 ? void 0 : _c.c;
 (_e = (_d = o4.b) === null || _d === void 0 ? void 0 : _d.c.d) === null || _e === void 0 ? void 0 : _e.e;
 (_h = (_g = (_f = o5).b) === null || _g === void 0 ? void 0 : _g.call(_f).c.d) === null || _h === void 0 ? void 0 : _h.e;
 (_j = o6()) === null || _j === void 0 ? void 0 : _j.x;
+// GH#34109
+((_k = o1) === null || _k === void 0 ? void 0 : _k.b) ? 1 : 0;
diff --git a/tests/baselines/reference/propertyAccessChain.symbols b/tests/baselines/reference/propertyAccessChain.symbols
@@ -79,3 +79,9 @@ o6<number>()?.x;
 >o6 : Symbol(o6, Decl(propertyAccessChain.ts, 16, 13))
 >x : Symbol(x, Decl(propertyAccessChain.ts, 16, 41))
 
+// GH#34109
+o1?.b ? 1 : 0;
+>o1?.b : Symbol(b, Decl(propertyAccessChain.ts, 0, 31))
+>o1 : Symbol(o1, Decl(propertyAccessChain.ts, 0, 13))
+>b : Symbol(b, Decl(propertyAccessChain.ts, 0, 31))
+
diff --git a/tests/baselines/reference/propertyAccessChain.types b/tests/baselines/reference/propertyAccessChain.types
@@ -80,3 +80,12 @@ o6<number>()?.x;
 >o6 : <T>() => { x: number; } | undefined
 >x : number | undefined
 
+// GH#34109
+o1?.b ? 1 : 0;
+>o1?.b ? 1 : 0 : 0 | 1
+>o1?.b : string | undefined
+>o1 : { b: string; } | undefined
+>b : string | undefined
+>1 : 1
+>0 : 0
+
diff --git a/tests/cases/conformance/expressions/optionalChaining/propertyAccessChain/propertyAccessChain.ts b/tests/cases/conformance/expressions/optionalChaining/propertyAccessChain/propertyAccessChain.ts
@@ -17,4 +17,7 @@ o5.b?.().c.d?.e;
 
 // GH#33744
 declare const o6: <T>() => undefined | ({ x: number });
-o6<number>()?.x;
+o6<number>()?.x;
+
+// GH#34109
+o1?.b ? 1 : 0;

Original file line number	Diff line number	Diff line change
`@@ -4739,7 +4739,7 @@ namespace ts {`
`4739`	`4739`	`const conditionalPrecedence = getOperatorPrecedence(SyntaxKind.ConditionalExpression, SyntaxKind.QuestionToken);`
`4740`	`4740`	`const emittedCondition = skipPartiallyEmittedExpressions(condition);`
`4741`	`4741`	`const conditionPrecedence = getExpressionPrecedence(emittedCondition);`
`4742`		`- if (compareValues(conditionPrecedence, conditionalPrecedence) === Comparison.LessThan) {`
	`4742`	`+ if (compareValues(conditionPrecedence, conditionalPrecedence) !== Comparison.GreaterThan) {`
`4743`	`4743`	`return createParen(condition);`
`4744`	`4744`	`}`
`4745`	`4745`	`return condition;`