Merge pull request #27176 from a-tarasyuk/bug/26786-no-error-when-using-allowjs-with-composite

#26786: deny using allowJs option with composite

src/compiler/program.ts

@@ -2609,8 +2609,8 @@ namespace ts {
                 }
             }
 
-            if (!options.noEmit && options.allowJs && options.declaration) {
-                createDiagnosticForOptionName(Diagnostics.Option_0_cannot_be_specified_with_option_1, "allowJs", "declaration");
+            if (!options.noEmit && options.allowJs && getEmitDeclarations(options)) {
+                createDiagnosticForOptionName(Diagnostics.Option_0_cannot_be_specified_with_option_1, "allowJs", options.declaration ? "declaration" : "composite");
             }
 
             if (options.checkJs && !options.allowJs) {

tests/baselines/reference/jsFileCompilationWithEnabledCompositeOption.errors.txt

@@ -0,0 +1,12 @@
+error TS5053: Option 'allowJs' cannot be specified with option 'composite'.
+
+
+!!! error TS5053: Option 'allowJs' cannot be specified with option 'composite'.
+==== tests/cases/compiler/a.ts (0 errors) ====
+    class c {
+    }
+    
+==== tests/cases/compiler/b.js (0 errors) ====
+    function foo() {
+    }
+    

tests/baselines/reference/jsFileCompilationWithEnabledCompositeOption.js

@@ -0,0 +1,24 @@
+//// [tests/cases/compiler/jsFileCompilationWithEnabledCompositeOption.ts] ////
+
+//// [a.ts]
+class c {
+}
+
+//// [b.js]
+function foo() {
+}
+
+
+//// [out.js]
+var c = /** @class */ (function () {
+    function c() {
+    }
+    return c;
+}());
+function foo() {
+}
+
+
+//// [out.d.ts]
+declare class c {
+}

tests/baselines/reference/jsFileCompilationWithEnabledCompositeOption.symbols

@@ -0,0 +1,10 @@
+=== tests/cases/compiler/a.ts ===
+class c {
+>c : Symbol(c, Decl(a.ts, 0, 0))
+}
+
+=== tests/cases/compiler/b.js ===
+function foo() {
+>foo : Symbol(foo, Decl(b.js, 0, 0))
+}
+

tests/baselines/reference/jsFileCompilationWithEnabledCompositeOption.types

@@ -0,0 +1,10 @@
+=== tests/cases/compiler/a.ts ===
+class c {
+>c : c
+}
+
+=== tests/cases/compiler/b.js ===
+function foo() {
+>foo : () => void
+}
+

tests/cases/compiler/jsFileCompilationWithEnabledCompositeOption.ts

@@ -0,0 +1,10 @@
+// @allowJs: true
+// @out: out.js
+// @composite: true
+// @filename: a.ts
+class c {
+}
+
+// @filename: b.js
+function foo() {
+}