fix unit tetss

Author: hansl

packages/ast-tools/src/change.spec.ts

@@ -96,6 +96,17 @@ describe('Change', () => {
       let sourceFile = path.join(sourcePath, 'remove-replace-file.txt');
       expect(() => new ReplaceChange(sourceFile, -6, 'hello', ' world!')).toThrow();
     });
+    it('fails for invalid replacement', () => {
+      let sourceFile = path.join(sourcePath, 'replace-file.txt');
+      let changeInstance = new ReplaceChange(sourceFile, 0, 'foobar', '');
+      return changeInstance
+        .apply(NodeHost)
+        .then(() => expect(false).toBe(true), err => {
+          // Check that the message contains the string to replace and the string from the file.
+          expect(err.message).toContain('foobar');
+          expect(err.message).toContain('import');
+        });
+    });
     it('adds string to the position of an empty string', () => {
       let sourceFile = path.join(sourcePath, 'replace-file.txt');
       let changeInstance = new ReplaceChange(sourceFile, 9, '', 'BarComponent, ');
@@ -108,7 +119,7 @@ describe('Change', () => {
     });
     it('removes the given string only if an empty string to add is given', () => {
       let sourceFile = path.join(sourcePath, 'remove-replace-file.txt');
-      let changeInstance = new ReplaceChange(sourceFile, 9, ' as foo', '');
+      let changeInstance = new ReplaceChange(sourceFile, 8, ' as foo', '');
       return changeInstance
         .apply(NodeHost)
         .then(() => readFile(sourceFile, 'utf8'))

packages/ast-tools/src/change.ts

@@ -156,11 +156,10 @@ export class ReplaceChange implements Change {
     return host.read(this.path).then(content => {
       const prefix = content.substring(0, this.pos);
       const suffix = content.substring(this.pos + this.oldText.length);
-      const replacedText = content.substring(this.pos,
-          this.pos + this.oldText.length) !== this.oldText;
+      const text = content.substring(this.pos, this.pos + this.oldText.length);
 
-      if (replacedText) {
-        throw new Error(`Invalid replace: "${replacedText}" != "${this.oldText}".`);
+      if (text !== this.oldText) {
+        return Promise.reject(new Error(`Invalid replace: "${text}" != "${this.oldText}".`));
       }
       // TODO: throw error if oldText doesn't match removed string.
       return host.write(this.path, `${prefix}${this.newText}${suffix}`);