feat(beforeAdd): allow custom script before git add

fix #331

bin/gh-pages.js

@@ -70,6 +70,10 @@ function main(args) {
         '-f, --no-history',
         'Push force new commit without parent history'
       )
+      .option(
+        '--before-add <file>',
+        'Execute the function exported by <file> before "git add"'
+      )
       .parse(args);
 
     let user;
@@ -83,6 +87,23 @@ function main(args) {
       }
       user = {name: parts.name, email: parts.address};
     }
+    let beforeAdd;
+    if (program.beforeAdd) {
+      const m = require(require.resolve(program.beforeAdd, {
+        paths: [process.cwd()]
+      }));
+
+      if (typeof m === 'function') {
+        beforeAdd = m;
+      } else if (typeof m === 'object' && typeof m.default === 'function') {
+        beforeAdd = m.default;
+      } else {
+        throw new Error(
+          `Could not find function to execute before adding files in ` +
+            `"${program.beforeAdd}".\n `
+        );
+      }
+    }
 
     const config = {
       repo: program.repo,
@@ -100,7 +121,8 @@ function main(args) {
       remote: program.remote,
       push: !!program.push,
       history: !!program.history,
-      user: user
+      user: user,
+      beforeAdd: beforeAdd
     };
 
     return publish(config);

lib/index.js

@@ -176,6 +176,11 @@ exports.publish = function publish(basePath, config, callback) {
           }
         );
       })
+      .then(git => {
+        return Promise.resolve(
+          options.beforeAdd && options.beforeAdd(git)
+        ).then(() => git);
+      })
       .then(git => {
         log('Adding all');
         return git.add('.');

readme.md

@@ -289,6 +289,35 @@ ghpages.publish('dist', {
 ```
 
 
+#### <a id="optionsbeforeadd">options.beforeAdd</a>
+ * type: `function`
+ * default: `null`
+
+Custom callback that is executed right before `git add`.
+
+The CLI expects a file exporting the beforeAdd function
+
+```bash
+gh-pages --before-add ./cleanup.js
+```
+
+Example use of the `beforeAdd` option:
+
+```js
+/**
+ * beforeAdd makes most sense when `add` option is active
+ * Assuming we want to keep everything on the gh-pages branch
+ * but remove just `some-outdated-file.txt`
+ */
+ghpages.publish('dist', {
+  add: true,
+  async beforeAdd(git) {
+    return git.rm('./some-outdated-file.txt');
+  }
+}, callback);
+```
+
+
 #### <a id="optionsgit">options.git</a>
  * type: `string`
  * default: `'git'`

test/bin/fixtures/beforeAdd.js

@@ -0,0 +1,3 @@
+module.exports = function myBeforeAdd() {
+  /* noop */
+};

test/bin/gh-pages.spec.js

@@ -2,6 +2,7 @@ const ghpages = require('../../lib/index');
 const sinon = require('sinon');
 const cli = require('../../bin/gh-pages');
 const assert = require('../helper').assert;
+const beforeAdd = require('./fixtures/beforeAdd');
 
 describe('gh-pages', () => {
   describe('main', () => {
@@ -71,6 +72,16 @@ describe('gh-pages', () => {
         dist: 'lib',
         config: {user: {name: 'Full Name', email: 'email@example.com'}}
       },
+      {
+        args: [
+          '--dist',
+          'lib',
+          '--before-add',
+          require.resolve('./fixtures/beforeAdd')
+        ],
+        dist: 'lib',
+        config: {beforeAdd}
+      },
       {
         args: ['--dist', 'lib', '-u', 'junk email'],
         dist: 'lib',

test/integration/beforeAdd.spec.js

@@ -0,0 +1,41 @@
+const helper = require('../helper');
+const ghPages = require('../../lib/');
+const path = require('path');
+
+const fixtures = path.join(__dirname, 'fixtures');
+const fixtureName = 'beforeAdd';
+
+beforeEach(() => {
+  ghPages.clean();
+});
+
+describe('the beforeAdd option', () => {
+  it('runs a provided async function before adding files', done => {
+    const local = path.join(fixtures, fixtureName, 'local');
+    const expected = path.join(fixtures, fixtureName, 'expected');
+    const branch = 'gh-pages';
+
+    helper.setupRemote(fixtureName, {branch}).then(url => {
+      const options = {
+        repo: url,
+        add: true,
+        async beforeAdd(git) {
+          return git.rm('hello-outdated-world.txt');
+        },
+        user: {
+          name: 'User Name',
+          email: 'user@email.com'
+        }
+      };
+      ghPages.publish(local, options, err => {
+        if (err) {
+          return done(err);
+        }
+        helper
+          .assertContentsMatch(expected, url, branch)
+          .then(() => done())
+          .catch(done);
+      });
+    });
+  });
+});

test/integration/fixtures/beforeAdd/expected/hello-old-world.txt

@@ -0,0 +1 @@
+Hello Old World!

test/integration/fixtures/beforeAdd/expected/hello-world.txt

@@ -0,0 +1 @@
+Hello World!

test/integration/fixtures/beforeAdd/local/hello-world.txt

@@ -0,0 +1 @@
+Hello World!

test/integration/fixtures/beforeAdd/remote/hello-old-world.txt

@@ -0,0 +1 @@
+Hello Old World!

test/integration/fixtures/beforeAdd/remote/hello-outdated-world.txt

@@ -0,0 +1 @@
+Hello Outdated World!