Add set filename option (#169)

* Add set filename option

* Update readme

README.md

@@ -27,6 +27,7 @@ You can pass options to `metalsmith-in-place` with the [Javascript API](https://
 * [pattern](#pattern): optional. Only files that match this pattern will be processed. Accepts a string or an array of strings. The default is `**`.
 * [engineOptions](#engineoptions): optional. Use this to pass options to the jstransformer that's rendering your files. The default is `{}`.
 * [suppressNoFilesError](#suppressnofileserror): optional. The no-files-to-process error will be suppressed. The default is `false`.
+* [setFilename](#setfilename): optional. Some templating engines, like [pug](https://github.com/pugjs/pug), need a `filename` property to be present in the options to be able to process relative includes, extends, etc. Setting this option to `true` will add the current filename to the options passed to each jstransformer. The default is `false`.
 
 ### `pattern`
 
@@ -71,9 +72,39 @@ Would pass `{ "cache": false }` to each used jstransformer.
 
 ### `suppressNoFilesError`
 
-`metalsmith-in-place` throws [an error](#no-files-to-process) if it can’t find any files to process. If you’re doing any kind of incremental builds via something like `metalsmith-watch`, this is problematic as you’re likely only rebuilding files that have changed. This flag allows you to suppress that error ([more info](https://github.com/metalsmith/metalsmith-in-place/pull/151)).
+`metalsmith-in-place` exits with [an error](#no-files-to-process) if it can’t find any files to process. If you’re doing any kind of incremental builds via something like `metalsmith-watch`, this is problematic as you’re likely only rebuilding files that have changed. This flag allows you to suppress that error. So this `metalsmith.json`:
 
-Note that if you have [debugging](#errors-and-debugging) turned on, you’ll see a message denoting that no files are present for processing.
+```json
+{
+  "source": "src",
+  "destination": "build",
+  "plugins": {
+    "metalsmith-in-place": {
+      "suppressNoFilesError": true
+    }
+  }
+}
+```
+
+Would suppress the error if there aren't any files to process. Note that when this option is turned on, if you're logging [debug messages](#errors-and-debugging), you’ll still see a message denoting when there aren't any files for metalsmith-layouts to process.
+
+### `setFilename`
+
+Set this option to `true` if you want to pass the current filename to each jstransformer. The default is `false`. So this `metalsmith.json`:
+
+```json
+{
+  "source": "src",
+  "destination": "build",
+  "plugins": {
+    "metalsmith-in-place": {
+      "setFilename": true
+    }
+  }
+}
+```
+
+Would overwrite `engineOptions.filename` with the absolute path for the file that's currently being processed, and pass that to the jstransformer. For now we're just passing `filename`, but if you encounter a jstransformer that requires a different property, like `path` or something else, let us know and we can add it.
 
 ## Errors and debugging
 

lib/index.js

@@ -1,3 +1,4 @@
+const path = require('path');
 const debug = require('debug')('metalsmith-in-place');
 const match = require('multimatch');
 const isUtf8 = require('is-utf8');
@@ -7,9 +8,11 @@ const getTransformer = require('./get-transformer');
  * Engine, renders file contents with all available transformers
  */
 
-function render({ filename, files, metadata, engineOptions }) {
+function render({ filename, files, metalsmith, settings }) {
   const [base, ...extensions] = filename.split('.');
   const file = files[filename];
+  const engineOptions = Object.assign({}, settings.engineOptions);
+  const metadata = metalsmith.metadata();
 
   debug(`rendering ${filename}`);
 
@@ -24,32 +27,38 @@ function render({ filename, files, metadata, engineOptions }) {
   }
 
   // Stringify file contents
-  file.contents = file.contents.toString();
+  const contents = file.contents.toString();
 
   // If this is the last extension, replace it with a new one
   if (extensions.length === 0) {
     debug(`last extension reached, replacing last extension with ${transform.outputFormat}`);
     extensions.push(transform.outputFormat);
   }
 
+  // Check if the filename should be set in the engine options
+  if (settings.setFilename) {
+    debug(`setting filename in the engine options`);
+    engineOptions.filename = path.join(metalsmith.source(), filename);
+  }
+
   // Transform the contents
   debug(`rendering ${ext} extension for ${filename}`);
 
   return transform
-    .renderAsync(file.contents, engineOptions, locals)
+    .renderAsync(contents, engineOptions, locals)
     .then(rendered => {
-      // Update contents and delete old file
-      file.contents = Buffer.from(rendered.body);
+      // Delete old file
       delete files[filename]; // eslint-disable-line no-param-reassign
 
       // Update files with the newly rendered file
       const newName = [base, ...extensions].join('.');
       files[newName] = file; // eslint-disable-line no-param-reassign
+      files[newName].contents = Buffer.from(rendered.body); // eslint-disable-line no-param-reassign
 
       debug(`done rendering ${filename}, renamed to ${newName}`);
 
       // Keep rendering until there are no applicable transformers left
-      return render({ filename: newName, files, metadata, engineOptions });
+      return render({ filename: newName, files, metalsmith, settings });
     })
     .catch(err => {
       err.message = `${filename}: ${err.message}`; // eslint-disable-line no-param-reassign
@@ -95,10 +104,10 @@ module.exports = options => (files, metalsmith, done) => {
   const defaults = {
     pattern: '**',
     engineOptions: {},
-    suppressNoFilesError: false
+    suppressNoFilesError: false,
+    setFilename: false
   };
   const settings = Object.assign({}, defaults, options);
-  const metadata = metalsmith.metadata();
 
   // Check whether the pattern option is valid
   if (!(typeof settings.pattern === 'string' || Array.isArray(settings.pattern))) {
@@ -116,22 +125,18 @@ module.exports = options => (files, metalsmith, done) => {
 
   // Let the user know when there are no files to process, usually caused by missing jstransformer
   if (validFiles.length === 0) {
-    const msg =
+    const message =
       'no files to process. See https://www.npmjs.com/package/metalsmith-in-place#no-files-to-process';
     if (settings.suppressNoFilesError) {
-      debug(msg);
+      debug(message);
       done();
     } else {
-      done(new Error(msg));
+      done(new Error(message));
     }
   }
 
   // Map all files that should be processed to an array of promises and call done when finished
-  Promise.all(
-    validFiles.map(filename =>
-      render({ filename, files, metadata, engineOptions: settings.engineOptions })
-    )
-  )
+  Promise.all(validFiles.map(filename => render({ filename, files, metalsmith, settings })))
     .then(() => done())
     .catch(/* istanbul ignore next */ error => done(error));
 };

lib/index.test.js

@@ -236,4 +236,21 @@ describe('metalsmith-in-place', () => {
       done();
     });
   });
+
+  it('should accept an option to set the filename in engine options', done => {
+    const base = path.join(process.cwd(), 'test', 'fixtures', 'set-filename');
+    const actual = path.join(base, 'build');
+    const expected = path.join(base, 'expected');
+    const metalsmith = new Metalsmith(base);
+
+    rimraf.sync(actual);
+
+    return metalsmith.use(plugin({ setFilename: true })).build(err => {
+      if (err) {
+        return done(err);
+      }
+      expect(() => equal(actual, expected)).not.toThrow();
+      return done();
+    });
+  });
 });

package.json

@@ -57,6 +57,7 @@
     "inputformat-to-jstransformer": "^1.2.1",
     "is-utf8": "^0.2.1",
     "jstransformer": "^1.0.0",
+    "jstransformer-pug": "^0.3.0",
     "multimatch": "^3.0.0"
   }
 }

test/fixtures/set-filename/expected/index.html

@@ -0,0 +1 @@
+<!doctype html><html lang="en"><body><h1>This is a heading</h1></body></html>

test/fixtures/set-filename/src/index.pug

@@ -0,0 +1,4 @@
+extends ../templates/base.pug
+
+block content
+  h1 This is a heading

test/fixtures/set-filename/templates/base.pug

@@ -0,0 +1,4 @@
+<!doctype html>
+html(lang="en")
+  body
+    block content