fix(ecr-assets): give accurate error when Tokens are being used (#4255)

Fixes #3795.

Author: rix0rrr

packages/@aws-cdk/aws-ecr-assets/lib/image-asset.ts

@@ -70,8 +70,8 @@ export class DockerImageAsset extends cdk.Construct implements assets.IAsset {
   constructor(scope: cdk.Construct, id: string, props: DockerImageAssetProps) {
     super(scope, id);
 
-    // verify buildArgs do not use tokens in neither keys nor values
-    validateBuildArgs(props.buildArgs);
+    // none of the properties use tokens
+    validateProps(props);
 
     // resolve full path
     const dir = path.resolve(props.directory);
@@ -134,6 +134,16 @@ export class DockerImageAsset extends cdk.Construct implements assets.IAsset {
   }
 }
 
+function validateProps(props: DockerImageAssetProps) {
+  for (const [key, value] of Object.entries(props)) {
+    if (Token.isUnresolved(value)) {
+      throw new Error(`Cannot use Token as value of '${key}': this value is used before deployment starts`);
+    }
+  }
+
+  validateBuildArgs(props.buildArgs);
+}
+
 function validateBuildArgs(buildArgs?: { [key: string]: string }) {
   for (const [key, value] of Object.entries(buildArgs || {})) {
     if (Token.isUnresolved(key) || Token.isUnresolved(value)) {

packages/@aws-cdk/aws-ecr-assets/test/test.image-asset.ts

@@ -233,6 +233,20 @@ export = {
       buildArgs: { key: token }
     }), expected);
 
+    test.done();
+  },
+
+  'fails if using token as repositoryName'(test: Test) {
+    // GIVEN
+    const stack = new Stack();
+    const token = Lazy.stringValue({ produce: () => 'foo' });
+
+    // THEN
+    test.throws(() => new DockerImageAsset(stack, 'MyAsset1', {
+      directory: path.join(__dirname, 'demo-image'),
+      repositoryName: token
+    }), /Cannot use Token as value of 'repositoryName'/);
+
     test.done();
   }
 };