Cherry-pick PR #42626 into release-4.2 (#42780)

Component commits:
214ef0c No did-you-mean-to-call error on casts
I chose to do the ad-hoc check rather than yet another tree walk.

1. It's faster to run and easier to read.
2. This error came from looking at real code. It happened twice, so I
think the best estimate for other uses that happened zero times is in
fact zero.
3. I couldn't think of other places to put the cast, given the
restrictions on `testedNode` just before the new code.

1d34778 Merge branch 'master' into no-did-you-mean-to-call-error-on-casts

Co-authored-by: Nathan Shively-Sanders <[email protected]>

Author: TypeScript Bot

src/compiler/checker.ts

@@ -34542,8 +34542,11 @@ namespace ts {
                 : isPropertyAccessExpression(location) ? location.name
                 : isBinaryExpression(location) && isIdentifier(location.right) ? location.right
                 : undefined;
+            const isPropertyExpressionCast = isPropertyAccessExpression(location)
+                && isParenthesizedExpression(location.expression)
+                && isAssertionExpression(location.expression.expression);
 
-            if (!testedNode) {
+            if (!testedNode || isPropertyExpressionCast) {
                 return;
             }
 

tests/baselines/reference/truthinessCallExpressionCoercion3.js

@@ -0,0 +1,19 @@
+//// [truthinessCallExpressionCoercion3.ts]
+// from #41640, based on an example in ant-design
+interface I {
+    always(): void
+}
+
+function f(result: unknown) {
+    if ((result as I).always) {
+        return result
+    }
+}
+
+
+//// [truthinessCallExpressionCoercion3.js]
+function f(result) {
+    if (result.always) {
+        return result;
+    }
+}

tests/baselines/reference/truthinessCallExpressionCoercion3.symbols

@@ -0,0 +1,24 @@
+=== tests/cases/compiler/truthinessCallExpressionCoercion3.ts ===
+// from #41640, based on an example in ant-design
+interface I {
+>I : Symbol(I, Decl(truthinessCallExpressionCoercion3.ts, 0, 0))
+
+    always(): void
+>always : Symbol(I.always, Decl(truthinessCallExpressionCoercion3.ts, 1, 13))
+}
+
+function f(result: unknown) {
+>f : Symbol(f, Decl(truthinessCallExpressionCoercion3.ts, 3, 1))
+>result : Symbol(result, Decl(truthinessCallExpressionCoercion3.ts, 5, 11))
+
+    if ((result as I).always) {
+>(result as I).always : Symbol(I.always, Decl(truthinessCallExpressionCoercion3.ts, 1, 13))
+>result : Symbol(result, Decl(truthinessCallExpressionCoercion3.ts, 5, 11))
+>I : Symbol(I, Decl(truthinessCallExpressionCoercion3.ts, 0, 0))
+>always : Symbol(I.always, Decl(truthinessCallExpressionCoercion3.ts, 1, 13))
+
+        return result
+>result : Symbol(result, Decl(truthinessCallExpressionCoercion3.ts, 5, 11))
+    }
+}
+

tests/baselines/reference/truthinessCallExpressionCoercion3.types

@@ -0,0 +1,23 @@
+=== tests/cases/compiler/truthinessCallExpressionCoercion3.ts ===
+// from #41640, based on an example in ant-design
+interface I {
+    always(): void
+>always : () => void
+}
+
+function f(result: unknown) {
+>f : (result: unknown) => unknown
+>result : unknown
+
+    if ((result as I).always) {
+>(result as I).always : () => void
+>(result as I) : I
+>result as I : I
+>result : unknown
+>always : () => void
+
+        return result
+>result : unknown
+    }
+}
+

tests/cases/compiler/truthinessCallExpressionCoercion3.ts

@@ -0,0 +1,13 @@
+// @strictNullChecks: true
+// @lib: esnext,dom
+
+// from #41640, based on an example in ant-design
+interface I {
+    always(): void
+}
+
+function f(result: unknown) {
+    if ((result as I).always) {
+        return result
+    }
+}