fix: no longer emit error for functions has no return statement under isolatedDeclarations

src/compiler/expressionToTypeNode.ts

@@ -484,7 +484,9 @@ export function createSyntacticTypeNodeBuilder(options: CompilerOptions, resolve
         if (declaration && !nodeIsMissing(declaration.body)) {
             const body = declaration.body;
             if (body && isBlock(body)) {
+                let hasReturn = false;
                 forEachReturnStatement(body, s => {
+                    hasReturn = true;
                     if (!candidateExpr) {
                         candidateExpr = s.expression;
                     }
@@ -493,6 +495,7 @@ export function createSyntacticTypeNodeBuilder(options: CompilerOptions, resolve
                         return true;
                     }
                 });
+                if (!hasReturn) return true; // it's void
             }
             else {
                 candidateExpr = body;

tests/baselines/reference/isolatedDeclarationErrorsAugmentation.errors.txt

@@ -1,8 +1,7 @@
-child1.ts(9,17): error TS9007: Function must have an explicit return type annotation with --isolatedDeclarations.
 parent.ts(1,1): error TS9026: Declaration emit for this file requires preserving this import for augmentations. This is not supported with --isolatedDeclarations.
 
 
-==== child1.ts (1 errors) ====
+==== child1.ts (0 errors) ====
     import { ParentThing } from './parent';
 
     declare module './parent' {
@@ -12,9 +11,6 @@ parent.ts(1,1): error TS9026: Declaration emit for this file requires preserving
     }
 
     export function child1(prototype: ParentThing) {
-                    ~~~~~~
-!!! error TS9007: Function must have an explicit return type annotation with --isolatedDeclarations.
-!!! related TS9031 child1.ts:9:17: Add a return type to the function declaration.
         prototype.add = (a: number, b: number) => a + b;
     }
 

tests/baselines/reference/isolatedDeclarationErrorsAugmentation.js

@@ -29,3 +29,13 @@ child1(ParentThing.prototype);
 export function child1(prototype) {
     prototype.add = (a, b) => a + b;
 }
+
+
+//// [child1.d.ts]
+import { ParentThing } from './parent';
+declare module './parent' {
+    interface ParentThing {
+        add: (a: number, b: number) => number;
+    }
+}
+export declare function child1(prototype: ParentThing): void;

tests/baselines/reference/isolatedDeclarationErrorsClasses.errors.txt

@@ -1,24 +1,24 @@
 isolatedDeclarationErrorsClasses.ts(3,5): error TS9012: Property must have an explicit type annotation with --isolatedDeclarations.
 isolatedDeclarationErrorsClasses.ts(4,5): error TS9008: Method must have an explicit return type annotation with --isolatedDeclarations.
-isolatedDeclarationErrorsClasses.ts(8,18): error TS7006: Parameter 'p' implicitly has an 'any' type.
-isolatedDeclarationErrorsClasses.ts(8,18): error TS9011: Parameter must have an explicit type annotation with --isolatedDeclarations.
-isolatedDeclarationErrorsClasses.ts(9,23): error TS9011: Parameter must have an explicit type annotation with --isolatedDeclarations.
-isolatedDeclarationErrorsClasses.ts(11,9): error TS9009: At least one accessor must have an explicit return type annotation with --isolatedDeclarations.
-isolatedDeclarationErrorsClasses.ts(12,9): error TS7032: Property 'setOnly' implicitly has type 'any', because its set accessor lacks a parameter type annotation.
-isolatedDeclarationErrorsClasses.ts(12,17): error TS7006: Parameter 'value' implicitly has an 'any' type.
-isolatedDeclarationErrorsClasses.ts(36,5): error TS1166: A computed property name in a class property declaration must have a simple literal type or a 'unique symbol' type.
-isolatedDeclarationErrorsClasses.ts(36,6): error TS2304: Cannot find name 'missing'.
-isolatedDeclarationErrorsClasses.ts(42,5): error TS9014: Computed properties must be number or string literals, variables or dotted expressions with --isolatedDeclarations.
-isolatedDeclarationErrorsClasses.ts(44,5): error TS9014: Computed properties must be number or string literals, variables or dotted expressions with --isolatedDeclarations.
-isolatedDeclarationErrorsClasses.ts(44,35): error TS7006: Parameter 'v' implicitly has an 'any' type.
-isolatedDeclarationErrorsClasses.ts(46,9): error TS9014: Computed properties must be number or string literals, variables or dotted expressions with --isolatedDeclarations.
-isolatedDeclarationErrorsClasses.ts(48,9): error TS7032: Property '[noParamAnnotationStringName]' implicitly has type 'any', because its set accessor lacks a parameter type annotation.
-isolatedDeclarationErrorsClasses.ts(48,9): error TS9014: Computed properties must be number or string literals, variables or dotted expressions with --isolatedDeclarations.
-isolatedDeclarationErrorsClasses.ts(48,39): error TS7006: Parameter 'value' implicitly has an 'any' type.
-isolatedDeclarationErrorsClasses.ts(50,5): error TS1166: A computed property name in a class property declaration must have a simple literal type or a 'unique symbol' type.
-isolatedDeclarationErrorsClasses.ts(55,5): error TS1169: A computed property name in an interface must refer to an expression whose type is a literal type or a 'unique symbol' type.
-isolatedDeclarationErrorsClasses.ts(56,5): error TS7010: '[noAnnotationLiteralName]', which lacks return-type annotation, implicitly has an 'any' return type.
-isolatedDeclarationErrorsClasses.ts(56,5): error TS9013: Expression type can't be inferred with --isolatedDeclarations.
+isolatedDeclarationErrorsClasses.ts(12,18): error TS7006: Parameter 'p' implicitly has an 'any' type.
+isolatedDeclarationErrorsClasses.ts(12,18): error TS9011: Parameter must have an explicit type annotation with --isolatedDeclarations.
+isolatedDeclarationErrorsClasses.ts(13,23): error TS9011: Parameter must have an explicit type annotation with --isolatedDeclarations.
+isolatedDeclarationErrorsClasses.ts(15,9): error TS9009: At least one accessor must have an explicit return type annotation with --isolatedDeclarations.
+isolatedDeclarationErrorsClasses.ts(16,9): error TS7032: Property 'setOnly' implicitly has type 'any', because its set accessor lacks a parameter type annotation.
+isolatedDeclarationErrorsClasses.ts(16,17): error TS7006: Parameter 'value' implicitly has an 'any' type.
+isolatedDeclarationErrorsClasses.ts(40,5): error TS1166: A computed property name in a class property declaration must have a simple literal type or a 'unique symbol' type.
+isolatedDeclarationErrorsClasses.ts(40,6): error TS2304: Cannot find name 'missing'.
+isolatedDeclarationErrorsClasses.ts(46,5): error TS9014: Computed properties must be number or string literals, variables or dotted expressions with --isolatedDeclarations.
+isolatedDeclarationErrorsClasses.ts(48,5): error TS9014: Computed properties must be number or string literals, variables or dotted expressions with --isolatedDeclarations.
+isolatedDeclarationErrorsClasses.ts(48,35): error TS7006: Parameter 'v' implicitly has an 'any' type.
+isolatedDeclarationErrorsClasses.ts(50,9): error TS9014: Computed properties must be number or string literals, variables or dotted expressions with --isolatedDeclarations.
+isolatedDeclarationErrorsClasses.ts(52,9): error TS7032: Property '[noParamAnnotationStringName]' implicitly has type 'any', because its set accessor lacks a parameter type annotation.
+isolatedDeclarationErrorsClasses.ts(52,9): error TS9014: Computed properties must be number or string literals, variables or dotted expressions with --isolatedDeclarations.
+isolatedDeclarationErrorsClasses.ts(52,39): error TS7006: Parameter 'value' implicitly has an 'any' type.
+isolatedDeclarationErrorsClasses.ts(54,5): error TS1166: A computed property name in a class property declaration must have a simple literal type or a 'unique symbol' type.
+isolatedDeclarationErrorsClasses.ts(59,5): error TS1169: A computed property name in an interface must refer to an expression whose type is a literal type or a 'unique symbol' type.
+isolatedDeclarationErrorsClasses.ts(60,5): error TS7010: '[noAnnotationLiteralName]', which lacks return-type annotation, implicitly has an 'any' return type.
+isolatedDeclarationErrorsClasses.ts(60,5): error TS9013: Expression type can't be inferred with --isolatedDeclarations.
 
 
 ==== isolatedDeclarationErrorsClasses.ts (21 errors) ====
@@ -28,28 +28,32 @@ isolatedDeclarationErrorsClasses.ts(56,5): error TS9013: Expression type can't b
         ~~~~~
 !!! error TS9012: Property must have an explicit type annotation with --isolatedDeclarations.
 !!! related TS9029 isolatedDeclarationErrorsClasses.ts:3:5: Add a type annotation to the property field.
-        method() {}
+        method() { return console.log() }
         ~~~~~~
 !!! error TS9008: Method must have an explicit return type annotation with --isolatedDeclarations.
 !!! related TS9034 isolatedDeclarationErrorsClasses.ts:4:5: Add a return type to the method
 
+        methodImplicitVoid() {
+            if (Math.random() > 0.5) console.log()
+            else console.log()
+        }
         methodOk(): void {}
 
         methodParams(p): void {}
                      ~
 !!! error TS7006: Parameter 'p' implicitly has an 'any' type.
                      ~
 !!! error TS9011: Parameter must have an explicit type annotation with --isolatedDeclarations.
-!!! related TS9028 isolatedDeclarationErrorsClasses.ts:8:18: Add a type annotation to the parameter p.
+!!! related TS9028 isolatedDeclarationErrorsClasses.ts:12:18: Add a type annotation to the parameter p.
         methodParams2(p = 1 + 1): void {}
                           ~~~~~
 !!! error TS9011: Parameter must have an explicit type annotation with --isolatedDeclarations.
-!!! related TS9028 isolatedDeclarationErrorsClasses.ts:9:19: Add a type annotation to the parameter p.
+!!! related TS9028 isolatedDeclarationErrorsClasses.ts:13:19: Add a type annotation to the parameter p.
 
         get getOnly() { return 1 + 1 }
             ~~~~~~~
 !!! error TS9009: At least one accessor must have an explicit return type annotation with --isolatedDeclarations.
-!!! related TS9032 isolatedDeclarationErrorsClasses.ts:11:9: Add a return type to the get accessor declaration.
+!!! related TS9032 isolatedDeclarationErrorsClasses.ts:15:9: Add a return type to the get accessor declaration.
         set setOnly(value) { }
             ~~~~~~~
 !!! error TS7032: Property 'setOnly' implicitly has type 'any', because its set accessor lacks a parameter type annotation.
@@ -83,7 +87,7 @@ isolatedDeclarationErrorsClasses.ts(56,5): error TS9013: Expression type can't b
 !!! error TS1166: A computed property name in a class property declaration must have a simple literal type or a 'unique symbol' type.
          ~~~~~~~
 !!! error TS2304: Cannot find name 'missing'.
-        
+
         [noAnnotationLiteralName](): void { }
 
         [noParamAnnotationLiteralName](v: string): void { }

tests/baselines/reference/isolatedDeclarationErrorsClasses.js

@@ -4,8 +4,12 @@
 export class Cls {
 
     field = 1 + 1;
-    method() {}
+    method() { return console.log() }
 
+    methodImplicitVoid() {
+        if (Math.random() > 0.5) console.log()
+        else console.log()
+    }
     methodOk(): void {}
 
     methodParams(p): void {}
@@ -37,7 +41,7 @@ export class C {
 
     // Should not be reported as an isolated declaration error
     [missing] = 1;
-    
+
     [noAnnotationLiteralName](): void { }
 
     [noParamAnnotationLiteralName](v: string): void { }
@@ -62,7 +66,13 @@ export interface I {
 //// [isolatedDeclarationErrorsClasses.js]
 export class Cls {
     field = 1 + 1;
-    method() { }
+    method() { return console.log(); }
+    methodImplicitVoid() {
+        if (Math.random() > 0.5)
+            console.log();
+        else
+            console.log();
+    }
     methodOk() { }
     methodParams(p) { }
     methodParams2(p = 1 + 1) { }