Issue unawaited promise error on symbol-less expressions (#44491)

* Issue unawaited promise error on symbol-less expressions

* Use same behavior for call expressions

* Revert "Use same behavior for call expressions"

This reverts commit 60d58132e4.

src/compiler/checker.ts

@@ -35870,15 +35870,14 @@ namespace ts {
             if (getFalsyFlags(type)) return;
 
             const location = isBinaryExpression(condExpr) ? condExpr.right : condExpr;
+            if (isPropertyAccessExpression(location) && isAssertionExpression(skipParentheses(location.expression))) {
+                return;
+            }
+
             const testedNode = isIdentifier(location) ? location
                 : isPropertyAccessExpression(location) ? location.name
                 : isBinaryExpression(location) && isIdentifier(location.right) ? location.right
                 : undefined;
-            const isPropertyExpressionCast = isPropertyAccessExpression(location)
-                && isAssertionExpression(skipParentheses(location.expression));
-            if (!testedNode || isPropertyExpressionCast) {
-                return;
-            }
 
             // While it technically should be invalid for any known-truthy value
             // to be tested, we de-scope to functions and Promises unreferenced in
@@ -35891,13 +35890,13 @@ namespace ts {
                 return;
             }
 
-            const testedSymbol = getSymbolAtLocation(testedNode);
-            if (!testedSymbol) {
+            const testedSymbol = testedNode && getSymbolAtLocation(testedNode);
+            if (!testedSymbol && !isPromise) {
                 return;
             }
 
-            const isUsed = isBinaryExpression(condExpr.parent) && isSymbolUsedInBinaryExpressionChain(condExpr.parent, testedSymbol)
-                || body && isSymbolUsedInConditionBody(condExpr, body, testedNode, testedSymbol);
+            const isUsed = testedSymbol && isBinaryExpression(condExpr.parent) && isSymbolUsedInBinaryExpressionChain(condExpr.parent, testedSymbol)
+                || testedSymbol && body && isSymbolUsedInConditionBody(condExpr, body, testedNode!, testedSymbol);
             if (!isUsed) {
                 if (isPromise) {
                     errorAndMaybeSuggestAwait(

tests/baselines/reference/truthinessPromiseCoercion.errors.txt

@@ -1,25 +1,28 @@
-tests/cases/compiler/truthinessPromiseCoercion.ts(6,9): error TS2801: This condition will always return true since this 'Promise<number>' is always defined.
-tests/cases/compiler/truthinessPromiseCoercion.ts(10,5): error TS2801: This condition will always return true since this 'Promise<number>' is always defined.
-tests/cases/compiler/truthinessPromiseCoercion.ts(31,9): error TS2801: This condition will always return true since this 'Promise<unknown>' is always defined.
+tests/cases/compiler/truthinessPromiseCoercion.ts(7,9): error TS2801: This condition will always return true since this 'Promise<number>' is always defined.
+tests/cases/compiler/truthinessPromiseCoercion.ts(11,5): error TS2801: This condition will always return true since this 'Promise<number>' is always defined.
+tests/cases/compiler/truthinessPromiseCoercion.ts(32,9): error TS2801: This condition will always return true since this 'Promise<unknown>' is always defined.
+tests/cases/compiler/truthinessPromiseCoercion.ts(40,9): error TS2801: This condition will always return true since this 'Promise<boolean>' is always defined.
+tests/cases/compiler/truthinessPromiseCoercion.ts(43,9): error TS2801: This condition will always return true since this 'Promise<boolean>' is always defined.
 
 
-==== tests/cases/compiler/truthinessPromiseCoercion.ts (3 errors) ====
+==== tests/cases/compiler/truthinessPromiseCoercion.ts (5 errors) ====
     declare const p: Promise<number>
     declare const p2: null | Promise<number>
     declare const obj: { p: Promise<unknown> }
+    declare function pf(): Promise<boolean>
     
     async function f() {
         if (p) {} // err
             ~
 !!! error TS2801: This condition will always return true since this 'Promise<number>' is always defined.
-!!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:6:9: Did you forget to use 'await'?
+!!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:7:9: Did you forget to use 'await'?
         if (!!p) {} // no err
         if (p2) {} // no err
     
         p ? f.arguments : f.arguments;
         ~
 !!! error TS2801: This condition will always return true since this 'Promise<number>' is always defined.
-!!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:10:5: Did you forget to use 'await'?
+!!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:11:5: Did you forget to use 'await'?
         !!p ? f.arguments : f.arguments;
         p2 ? f.arguments : f.arguments;
     }
@@ -43,10 +46,26 @@ tests/cases/compiler/truthinessPromiseCoercion.ts(31,9): error TS2801: This cond
         if (obj.p) {} // error
             ~~~~~
 !!! error TS2801: This condition will always return true since this 'Promise<unknown>' is always defined.
-!!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:31:9: Did you forget to use 'await'?
+!!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:32:9: Did you forget to use 'await'?
         if (obj.p) {  // ok
             await obj.p;
         }
         if (obj.p && await obj.p) {} // ok
     }
+    
+    async function i(): Promise<string> {
+        if (pf()) { // error
+            ~~~~
+!!! error TS2801: This condition will always return true since this 'Promise<boolean>' is always defined.
+!!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:40:9: Did you forget to use 'await'?
+            return "true";
+        }
+        if (pf()) { // error
+            ~~~~
+!!! error TS2801: This condition will always return true since this 'Promise<boolean>' is always defined.
+!!! related TS2773 tests/cases/compiler/truthinessPromiseCoercion.ts:43:9: Did you forget to use 'await'?
+            pf().then();
+        }
+        return "false";
+    }
     

tests/baselines/reference/truthinessPromiseCoercion.js

@@ -2,6 +2,7 @@
 declare const p: Promise<number>
 declare const p2: null | Promise<number>
 declare const obj: { p: Promise<unknown> }
+declare function pf(): Promise<boolean>
 
 async function f() {
     if (p) {} // err
@@ -35,6 +36,16 @@ async function h() {
     }
     if (obj.p && await obj.p) {} // ok
 }
+
+async function i(): Promise<string> {
+    if (pf()) { // error
+        return "true";
+    }
+    if (pf()) { // error
+        pf().then();
+    }
+    return "false";
+}
 
 
 //// [truthinessPromiseCoercion.js]
@@ -67,3 +78,12 @@ async function h() {
     }
     if (obj.p && await obj.p) { } // ok
 }
+async function i() {
+    if (pf()) { // error
+        return "true";
+    }
+    if (pf()) { // error
+        pf().then();
+    }
+    return "false";
+}

tests/baselines/reference/truthinessPromiseCoercion.symbols

@@ -12,8 +12,12 @@ declare const obj: { p: Promise<unknown> }
 >p : Symbol(p, Decl(truthinessPromiseCoercion.ts, 2, 20))
 >Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
 
+declare function pf(): Promise<boolean>
+>pf : Symbol(pf, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
+
 async function f() {
->f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 3, 39))
 
     if (p) {} // err
 >p : Symbol(p, Decl(truthinessPromiseCoercion.ts, 0, 13))
@@ -27,34 +31,34 @@ async function f() {
     p ? f.arguments : f.arguments;
 >p : Symbol(p, Decl(truthinessPromiseCoercion.ts, 0, 13))
 >f.arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
->f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 3, 39))
 >arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
 >f.arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
->f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 3, 39))
 >arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
 
     !!p ? f.arguments : f.arguments;
 >p : Symbol(p, Decl(truthinessPromiseCoercion.ts, 0, 13))
 >f.arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
->f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 3, 39))
 >arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
 >f.arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
->f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 3, 39))
 >arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
 
     p2 ? f.arguments : f.arguments;
 >p2 : Symbol(p2, Decl(truthinessPromiseCoercion.ts, 1, 13))
 >f.arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
->f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 3, 39))
 >arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
 >f.arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
->f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>f : Symbol(f, Decl(truthinessPromiseCoercion.ts, 3, 39))
 >arguments : Symbol(Function.arguments, Decl(lib.es5.d.ts, --, --))
 }
 
 // all ok
 async function g() {
->g : Symbol(g, Decl(truthinessPromiseCoercion.ts, 12, 1))
+>g : Symbol(g, Decl(truthinessPromiseCoercion.ts, 13, 1))
 
     if (p) {
 >p : Symbol(p, Decl(truthinessPromiseCoercion.ts, 0, 13))
@@ -87,7 +91,7 @@ async function g() {
 }
 
 async function h() {
->h : Symbol(h, Decl(truthinessPromiseCoercion.ts, 27, 1))
+>h : Symbol(h, Decl(truthinessPromiseCoercion.ts, 28, 1))
 
     if (obj.p) {} // error
 >obj.p : Symbol(p, Decl(truthinessPromiseCoercion.ts, 2, 20))
@@ -113,3 +117,23 @@ async function h() {
 >p : Symbol(p, Decl(truthinessPromiseCoercion.ts, 2, 20))
 }
 
+async function i(): Promise<string> {
+>i : Symbol(i, Decl(truthinessPromiseCoercion.ts, 36, 1))
+>Promise : Symbol(Promise, Decl(lib.es5.d.ts, --, --), Decl(lib.es2015.iterable.d.ts, --, --), Decl(lib.es2015.promise.d.ts, --, --), Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2018.promise.d.ts, --, --))
+
+    if (pf()) { // error
+>pf : Symbol(pf, Decl(truthinessPromiseCoercion.ts, 2, 42))
+
+        return "true";
+    }
+    if (pf()) { // error
+>pf : Symbol(pf, Decl(truthinessPromiseCoercion.ts, 2, 42))
+
+        pf().then();
+>pf().then : Symbol(Promise.then, Decl(lib.es5.d.ts, --, --))
+>pf : Symbol(pf, Decl(truthinessPromiseCoercion.ts, 2, 42))
+>then : Symbol(Promise.then, Decl(lib.es5.d.ts, --, --))
+    }
+    return "false";
+}
+

tests/baselines/reference/truthinessPromiseCoercion.types

@@ -10,6 +10,9 @@ declare const obj: { p: Promise<unknown> }
 >obj : { p: Promise<unknown>; }
 >p : Promise<unknown>
 
+declare function pf(): Promise<boolean>
+>pf : () => Promise<boolean>
+
 async function f() {
 >f : () => Promise<void>
 
@@ -132,3 +135,28 @@ async function h() {
 >p : Promise<unknown>
 }
 
+async function i(): Promise<string> {
+>i : () => Promise<string>
+
+    if (pf()) { // error
+>pf() : Promise<boolean>
+>pf : () => Promise<boolean>
+
+        return "true";
+>"true" : "true"
+    }
+    if (pf()) { // error
+>pf() : Promise<boolean>
+>pf : () => Promise<boolean>
+
+        pf().then();
+>pf().then() : Promise<boolean>
+>pf().then : <TResult1 = boolean, TResult2 = never>(onfulfilled?: ((value: boolean) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | null | undefined) => Promise<TResult1 | TResult2>
+>pf() : Promise<boolean>
+>pf : () => Promise<boolean>
+>then : <TResult1 = boolean, TResult2 = never>(onfulfilled?: ((value: boolean) => TResult1 | PromiseLike<TResult1>) | null | undefined, onrejected?: ((reason: any) => TResult2 | PromiseLike<TResult2>) | null | undefined) => Promise<TResult1 | TResult2>
+    }
+    return "false";
+>"false" : "false"
+}
+

tests/cases/compiler/truthinessPromiseCoercion.ts

@@ -4,6 +4,7 @@
 declare const p: Promise<number>
 declare const p2: null | Promise<number>
 declare const obj: { p: Promise<unknown> }
+declare function pf(): Promise<boolean>
 
 async function f() {
     if (p) {} // err
@@ -37,3 +38,13 @@ async function h() {
     }
     if (obj.p && await obj.p) {} // ok
 }
+
+async function i(): Promise<string> {
+    if (pf()) { // error
+        return "true";
+    }
+    if (pf()) { // error
+        pf().then();
+    }
+    return "false";
+}