fix(compiler-cli): Fix swallowed Error messages (#20846)

This commit fixes a bug in which non-formatted errors are silently
dropped.

Internal issue: b/67739418

PR Close #20846

packages/compiler-cli/src/transformers/program.ts

@@ -869,17 +869,21 @@ function syntaxErrorToDiagnostics(error: Error): Diagnostic[] {
                                           source: SOURCE,
                                           code: DEFAULT_ERROR_CODE
                                         }));
-  } else {
+  } else if (isFormattedError(error)) {
-    if (isFormattedError(error)) {
+    return [{
-      return [{
+      messageText: error.message,
-        messageText: error.message,
+      chain: error.chain && diagnosticChainFromFormattedDiagnosticChain(error.chain),
-        chain: error.chain && diagnosticChainFromFormattedDiagnosticChain(error.chain),
+      category: ts.DiagnosticCategory.Error,
-        category: ts.DiagnosticCategory.Error,
+      source: SOURCE,
-        source: SOURCE,
+      code: DEFAULT_ERROR_CODE,
-        code: DEFAULT_ERROR_CODE,
+      position: error.position
-        position: error.position
+    }];
-      }];
-    }
   }
-  return [];
+  // Produce a Diagnostic anyway since we know for sure `error` is a SyntaxError
-}
+  return [{
+    messageText: error.message,
+    category: ts.DiagnosticCategory.Error,
+    code: DEFAULT_ERROR_CODE,
+    source: SOURCE,
+  }];
+}

packages/compiler-cli/test/transformers/program_spec.ts

@@ -948,6 +948,35 @@ describe('ng program', () => {
       });
     });
 
+    it('should include non-formatted errors (e.g. invalid templateUrl)', () => {
+      testSupport.write('src/index.ts', `
+        import {Component, NgModule} from '@angular/core';
+
+        @Component({
+          selector: 'my-component',
+          templateUrl: 'template.html',   // invalid template url
+        })
+        export class MyComponent {}
+
+        @NgModule({
+          declarations: [MyComponent]
+        })
+        export class MyModule {}
+      `);
+
+      const options = testSupport.createCompilerOptions();
+      const host = ng.createCompilerHost({options});
+      const program = ng.createProgram({
+        rootNames: [path.resolve(testSupport.basePath, 'src/index.ts')],
+        options,
+        host,
+      });
+
+      const structuralErrors = program.getNgStructuralDiagnostics();
+      expect(structuralErrors.length).toBe(1);
+      expect(structuralErrors[0].messageText).toContain('Couldn\'t resolve resource template.html');
+    });
+
     it('should be able report structural errors with noResolve:true and generateCodeForLibraries:false ' +
            'even if getSourceFile throws for non existent files',
        () => {