From a50f77604d2ecdde26f83b8aed8319cbb3d73ba4 Mon Sep 17 00:00:00 2001
From: Charles Lyding <19598772+clydin@users.noreply.github.com>
Date: Wed, 25 Jul 2018 12:28:24 -0400
Subject: [PATCH 1/2] fix(@angular-devkit/core): rename to itself should be a
 noop

---
 .../core/src/virtual-fs/host/record.ts        | 10 +++++---
 .../core/src/virtual-fs/host/record_spec.ts   | 23 +++++++++++++++++++
 2 files changed, 30 insertions(+), 3 deletions(-)

diff --git a/packages/angular_devkit/core/src/virtual-fs/host/record.ts b/packages/angular_devkit/core/src/virtual-fs/host/record.ts
index a03276e45f48..9c7d2597061d 100644
--- a/packages/angular_devkit/core/src/virtual-fs/host/record.ts
+++ b/packages/angular_devkit/core/src/virtual-fs/host/record.ts
@@ -271,12 +271,16 @@ export class CordHost extends SimpleMemoryHost {
     ).pipe(
       toArray(),
       switchMap(([existTo, existFrom]) => {
-        if (existTo) {
-          return throwError(new FileAlreadyExistException(to));
-        }
         if (!existFrom) {
           return throwError(new FileDoesNotExistException(from));
         }
+        if (from === to) {
+          return of();
+        }
+
+        if (existTo) {
+          return throwError(new FileAlreadyExistException(to));
+        }
 
         // If we're renaming a file that's been created, shortcircuit to creating the `to` path.
         if (this._filesToCreate.has(from)) {
diff --git a/packages/angular_devkit/core/src/virtual-fs/host/record_spec.ts b/packages/angular_devkit/core/src/virtual-fs/host/record_spec.ts
index 96ccf4ed7503..96b6b0e43eaa 100644
--- a/packages/angular_devkit/core/src/virtual-fs/host/record_spec.ts
+++ b/packages/angular_devkit/core/src/virtual-fs/host/record_spec.ts
@@ -101,6 +101,29 @@ describe('CordHost', () => {
     done();
   });
 
+  it('works (create -> rename (identity))', done => {
+    const base = new TestHost({
+      '/hello': 'world',
+    });
+
+    const host = new CordHost(base);
+    host.write(path`/blue`, fileBuffer`hi`).subscribe(undefined, done.fail);
+    host.rename(path`/blue`, path`/blue`).subscribe(undefined, done.fail);
+
+    const target = new TestHost();
+    host.commit(target).subscribe(undefined, done.fail);
+
+    // Check that there's only 1 write done.
+    expect(target.records.filter(x => mutatingTestRecord.includes(x.kind))).toEqual([
+      { kind: 'write', path: path`/blue` },
+    ]);
+
+    expect(target.$exists('/hello')).toBe(false);
+    expect(target.$exists('/blue')).toBe(true);
+
+    done();
+  });
+
   it('works (create -> rename -> rename)', done => {
     const base = new TestHost({
       '/hello': 'world',

From 4eb0bda6fb3947739210357ce6026112bf3948e7 Mon Sep 17 00:00:00 2001
From: Charles Lyding <19598772+clydin@users.noreply.github.com>
Date: Wed, 25 Jul 2018 12:35:41 -0400
Subject: [PATCH 2/2] fix(@angular-devkit/schematics): move rule with identity
 is a noop

---
 .../angular_devkit/schematics/src/rules/move.ts  |  5 +++++
 .../schematics/src/rules/move_spec.ts            | 16 ++++++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/packages/angular_devkit/schematics/src/rules/move.ts b/packages/angular_devkit/schematics/src/rules/move.ts
index b22e29b7cd76..96cfe15737fc 100644
--- a/packages/angular_devkit/schematics/src/rules/move.ts
+++ b/packages/angular_devkit/schematics/src/rules/move.ts
@@ -7,6 +7,7 @@
  */
 import { normalize } from '@angular-devkit/core';
 import { Rule } from '../engine/interface';
+import { noop } from './base';
 
 
 export function move(from: string, to?: string): Rule {
@@ -18,6 +19,10 @@ export function move(from: string, to?: string): Rule {
   const fromPath = normalize('/' + from);
   const toPath = normalize('/' + to);
 
+  if (fromPath === toPath) {
+    return noop;
+  }
+
   return tree => tree.visit(path => {
     if (path.startsWith(fromPath)) {
       tree.rename(path, toPath + '/' + path.substr(fromPath.length));
diff --git a/packages/angular_devkit/schematics/src/rules/move_spec.ts b/packages/angular_devkit/schematics/src/rules/move_spec.ts
index 113e90769fff..c9c67a23b357 100644
--- a/packages/angular_devkit/schematics/src/rules/move_spec.ts
+++ b/packages/angular_devkit/schematics/src/rules/move_spec.ts
@@ -48,4 +48,20 @@ describe('move', () => {
       })
       .then(done, done.fail);
   });
+
+  it('becomes a noop with identical from and to', done => {
+    const tree = new HostTree();
+    tree.create('a/b/file1', 'hello world');
+    tree.create('a/b/file2', 'hello world');
+    tree.create('a/c/file3', 'hello world');
+
+    callRule(move(''), observableOf(tree), context)
+      .toPromise()
+      .then(result => {
+        expect(result.exists('a/b/file1')).toBe(true);
+        expect(result.exists('a/b/file2')).toBe(true);
+        expect(result.exists('a/c/file3')).toBe(true);
+      })
+      .then(done, done.fail);
+  });
 });