feat!: Lookup configPath in configFiles (#128)

Author: phated

Diff for: README.md

@@ -165,6 +165,8 @@ Default: `null`
 
 An object of configuration files to find. Each property is keyed by the default basename of the file being found, and the value is an array of [path arguments](#path-arguments) of which the order indicates priority to find.
 
+See [Config Files](#config-files) for the config file specification.
+
 **Note:** This option is useful if, for example, you want to support an `.apprc` file in addition to an `appfile.js`. If you only need a single configuration file, you probably don't need this. In addition to letting you find multiple files, this option allows more fine-grained control over how configuration files are located.
 
 Type: `Object`
@@ -337,11 +339,7 @@ const onExecute = function (env, argv) {
 };
 const onPrepare = function (env) {
   const config = env.config['.hacker'];
-  if (config.hackerfile) {
-    env.configPath = path.resolve(config.hackerfile);
-    env.configBase = path.dirname(env.configPath);
-  }
-  Hacker.execute(env, onExecute);
+  Hacker.execute(env, config.forcedFlags, onExecute);
 };
 Hacker.prepare({}, onPrepare);
 ```
@@ -457,6 +455,7 @@ A function called after your environment is prepared. A good place to modify the
 - `modulePath`: the full path to the local module your project relies on (if found)
 - `modulePackage`: the contents of the local module's package.json (if found)
 - `configFiles`: an object of filepaths for each found config file (filepath values will be null if not found)
+- `config`: an object with keys matching `configFiles` but with the loaded config object
 
 ### execute(env, [forcedFlags], callback(env, argv))
 
@@ -492,6 +491,7 @@ A function called after your application is executed. When invoked, `this` will
 - `modulePath`: the full path to the local module your project relies on (if found)
 - `modulePackage`: the contents of the local module's package.json (if found)
 - `configFiles`: an object of filepaths for each found config file (filepath values will be null if not found)
+- `config`: an object with keys matching `configFiles` but with the loaded config object
 
 ### events
 
@@ -582,6 +582,18 @@ Hacker.on('respawn', function (flags, child) {
 Event will be triggered for this command:
 `hacker --harmony commmand`
 
+## Config files
+
+Liftoff supports a small definition of config files, but all details provided by users will be available in `env.config`.
+
+### `extends`
+
+All `extends` properties will be traversed and become the basis for the resulting config object. Any path provided for `extends` will be loaded with node's `require`, so all extensions and loaders supported on the Liftoff instance will be available to them.
+
+### Field matching the `configName`
+
+Users can override the `configPath` via their config files by specifying a field with the same name as the primary `configName`. For example, the `hackerfile` property in a `configFile` will resolve the `configPath` and `configBase` against the path.
+
 ## Examples
 
 Check out how [gulp][gulp-cli-index] uses Liftoff.

Diff for: index.js

@@ -50,6 +50,8 @@ Liftoff.prototype.buildEnvironment = function (opts) {
 
   // make a copy of search paths that can be mutated for this run
   var searchPaths = this.searchPaths.slice();
+  // store the instance configName to use in closures without access to `this`
+  var configName = this.configName;
 
   // calculate current cwd
   var cwd = findCwd(opts);
@@ -113,6 +115,13 @@ Liftoff.prototype.buildEnvironment = function (opts) {
         'Encountered error when loading config file: ' + configFilePath
       );
     }
+
+    // resolve something like `{ gulpfile: "./abc.xyz" }` to the absolute path
+    // based on the path of the configFile
+    if (Object.prototype.hasOwnProperty.call(configFile, configName)) {
+      configFile[configName] = path.resolve(path.dirname(configFilePath), configFile[configName]);
+    }
+
     visited[configFilePath] = true;
     if (configFile && configFile.extends) {
       var nextCwd = path.dirname(configFilePath);
@@ -146,6 +155,13 @@ Liftoff.prototype.buildEnvironment = function (opts) {
     return loadConfig(cwd, startingLocation, defaultConfig);
   });
 
+  var configPathOverride = arrayFind(Object.keys(config), function (key) {
+    var cfg = config[key];
+    if (Object.prototype.hasOwnProperty.call(cfg, configName)) {
+      return cfg[configName];
+    }
+  });
+
   // if cwd was provided explicitly, only use it for searching config
   if (opts.cwd) {
     searchPaths = [cwd];
@@ -156,15 +172,15 @@ Liftoff.prototype.buildEnvironment = function (opts) {
 
   // calculate the regex to use for finding the config file
   var configNameSearch = buildConfigName({
-    configName: this.configName,
+    configName: configName,
     extensions: Object.keys(this.extensions),
   });
 
   // calculate configPath
   var configPath = findConfig({
     configNameSearch: configNameSearch,
     searchPaths: searchPaths,
-    configPath: opts.configPath,
+    configPath: opts.configPath || configPathOverride,
   });
 
   // if we have a config path, save the directory it resides in.

Diff for: test/fixtures/configfiles/override-config-path-absolute.js

@@ -0,0 +1,5 @@
+var path = require('path');
+
+module.exports = {
+  myappfile: path.join(__dirname, "../override-the-config-path.js"),
+};

Diff for: test/fixtures/configfiles/override-config-path-relative.json

@@ -0,0 +1,3 @@
+{
+  "myappfile": "../override-the-config-path.js"
+}

Diff for: test/fixtures/override-the-config-path.js

@@ -571,6 +571,36 @@ describe('Liftoff', function () {
       );
     });
 
+    it('overrides the configPath if the configName key exists in the config', function (done) {
+      var app = new Liftoff({
+        name: 'myapp',
+        configFiles: {
+          'override-config-path-absolute': [
+            { path: 'test/fixtures/configfiles', extensions: ['.js'] }
+          ],
+        },
+      });
+      app.prepare({}, function (env) {
+        expect(env.configPath).toMatch(/override-the-config-path\.js$/);
+        done();
+      });
+    });
+
+    it('resolves relative configPath if the configName key exists in the config', function (done) {
+      var app = new Liftoff({
+        name: 'myapp',
+        configFiles: {
+          'override-config-path-relative': [
+            { path: 'test/fixtures/configfiles', extensions: ['.json'] }
+          ],
+        },
+      });
+      app.prepare({}, function (env) {
+        expect(env.configPath).toMatch(/override-the-config-path\.js$/);
+        done();
+      });
+    });
+
     it('should use dirname of configPath if no cwd is specified', function (done) {
       var app = new Liftoff({
         name: 'myapp',