Add append support to copy operation.

README.md

@@ -67,7 +67,9 @@ Copy a file from the `from` path to the `to` path.
 
 Optionally, pass an `options.process` function (`process(contents)`) returning a string or a buffer who'll become the new file content. The process function will take a single contents argument who is the copied file contents as a `Buffer`.
 
-`option.ignoreNoMatch` can be used to silence the error thrown if no files match the `from` pattern.
+`options.ignoreNoMatch` can be used to silence the error thrown if no files match the `from` pattern.
+
+`options.append` can be used to append `from` contents to `to` instead of copying.
 
 `from` can be a glob pattern that'll be match against the file system. If that's the case, then `to` must be an output directory. For a globified `from`, you can optionally pass in an `options.globOptions` object to change its pattern matching behavior. The full list of options are being described [here](https://github.com/mrmlnc/fast-glob#options-1). The `nodir` flag is forced to be `true` in `globOptions` to ensure a vinyl object representing each matching directory is marked as `deleted` in the `mem-fs` store.
 

__tests__/copy-tpl.js

@@ -38,6 +38,15 @@ describe('#copyTpl()', () => {
     expect(fs.read(newPath)).toBe('partial' + os.EOL + os.EOL);
   });
 
+  it('allow appending files', function () {
+    const filepath = path.join(__dirname, 'fixtures/file-tpl.txt');
+    const newPath = '/new/path/file-append.txt';
+    fs.copyTpl(filepath, newPath, {name: 'new content'});
+    expect(fs.read(newPath)).toBe('new content' + os.EOL);
+    fs.copyTpl(filepath, newPath, {name: 'new content'}, undefined, {append: true});
+    expect(fs.read(newPath)).toBe('new content' + os.EOL + 'new content' + os.EOL);
+  });
+
   it('allow including glob options', function () {
     const filenames = [
       path.join(__dirname, 'fixtures/file-tpl-partial.txt'),

__tests__/copy.js

@@ -25,6 +25,18 @@ describe('#copy()', () => {
     expect(fs.store.get(newPath).state).toBe('modified');
   });
 
+  it('append file', () => {
+    const filepath = path.join(__dirname, 'fixtures/file-a.txt');
+    const initialContents = fs.read(filepath);
+    const newPath = '/new/path/file.txt';
+    fs.copy(filepath, newPath);
+    expect(fs.read(newPath)).toBe(initialContents);
+    expect(fs.store.get(newPath).state).toBe('modified');
+
+    fs.copy(filepath, newPath, {append: true});
+    expect(fs.read(newPath)).toBe(initialContents + initialContents);
+  });
+
   it('can copy directory not commited to disk', () => {
     let sourceDir = path.join(__dirname, '../test/foo');
     let destDir = path.join(__dirname, '../test/bar');

lib/actions/copy.js

@@ -24,7 +24,7 @@ exports.copy = function (from, to, options, context, tplSettings) {
   var storeFiles = [];
   this.store.each(file => {
     // The store may have a glob path and when we try to copy it will fail because not real file
-    if (!globby.hasMagic(normalize(file.path)) && multimatch([file.path], fromGlob).length !== 0) {
+    if (!globby.hasMagic(normalize(file.path)) && multimatch([file.path], fromGlob).length !== 0 && !diskFiles.includes(file.path)) {
       storeFiles.push(file.path);
     }
   });
@@ -69,5 +69,10 @@ exports._copySingle = function (from, to, options, context, tplSettings) {
     to = ejs.render(to, context, tplSettings);
   }
 
+  if (options.append) {
+    this.append(to, contents, options);
+    return;
+  }
+
   this.write(to, contents, file.stat);
 };