fix(bazel): improve error message for missing assets

packages/bazel/src/ngc-wrapped/index.ts

@@ -202,6 +202,12 @@ export function compile({allowNonHermeticReads, allDepsCompiledWithBazel = true,
       return path.resolve(bazelBin, workspaceRelative) + '.d.ts';
     };
   }
+  // Patch a property on the ngHost that allows the resourceNameToModuleName function to
+  // report better errors.
+  (ngHost as any).reportMissingResource = (resourceName: string) => {
+    console.error(`\nAsset not found:\n  ${resourceName}`);
+    console.error('Check that it\'s included in the `assets` attribute of the `ng_module` rule.\n');
+  };
 
   const emitCallback: ng.TsEmitCallback = ({
     program,

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

@@ -231,7 +231,12 @@ export class TsCompilerAotCompilerTypeCheckHostAdapter implements ts.CompilerHos
     }
     const filePathWithNgResource =
         this.moduleNameToFileName(addNgResourceSuffix(resourceName), containingFile);
-    return filePathWithNgResource ? stripNgResourceSuffix(filePathWithNgResource) : null;
+    const result = filePathWithNgResource ? stripNgResourceSuffix(filePathWithNgResource) : null;
+    // Used under Bazel to report more specific error with remediation advice
+    if (!result && (this.context as any).reportMissingResource) {
+      (this.context as any).reportMissingResource(resourceName);
+    }
+    return result;
   }
 
   toSummaryFileName(fileName: string, referringSrcFileName: string): string {