feat: the default banner is the LICENSE file

LICENSE

@@ -0,0 +1,21 @@
+The MIT License (MIT)
+
+Copyright (c) 2016 Mickael Jeanroy
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

src/index.js

@@ -31,62 +31,71 @@ const MagicString = require('magic-string');
 
 const EOL = '\n';
 
-module.exports = (options) => {
+module.exports = (options = {}) => {
   return {
     transformBundle(code) {
-      const file = path.resolve(options.file);
+      const file = options.file || 'LICENSE';
+      const filePath = path.resolve(file);
 
       const deferred = Q.defer();
 
-      fs.readFile(file, 'utf-8', (error, content) => {
-        if (error) {
-          return deferred.reject(error);
+      fs.exists(filePath, (exists) => {
+        if (!exists) {
+          deferred.reject(new Error(`File ${filePath} does not exist`));
+          return;
         }
 
-        // Import the `package.json` of the project.
-        // The `resolve` function
-        const pkgPath = path.resolve(process.cwd(), 'package.json');
-        const pkg = require(pkgPath);
-
-        // Create the template function with lodash.
-        const tmpl = _.template(content);
-
-        // Generate the banner.
-        let banner = tmpl({_, moment, pkg});
-
-        // Make a block comment if needed
-        const trimmedBanner = banner.trim();
-        const start = trimmedBanner.slice(0, 3);
-        if (start !== '/**') {
-          const bannerContent = trimmedBanner
-            .split(`${EOL}`)
-            .map((line) => _.trimEnd(` * ${line}`))
-            .join(`${EOL}`);
-
-          banner = `/**${EOL}${bannerContent}${EOL} */${EOL}`;
-        }
-
-        // Create a magicString: do not manipulate the string directly since it
-        // will be used to generate the sourcemap.
-        const magicString = new MagicString(code);
-
-        // Prepend the banner.
-        magicString.prepend(`${banner}${EOL}`);
-
-        // Create the result object.
-        const result = {
-          code: magicString.toString(),
-        };
-
-        // Add sourceMap information if it is enabled.
-        if (options.sourceMap !== false) {
-          result.map = magicString.generateMap({
-            hires: true,
-          });
-        }
-
-        // Everything is ok.
-        return deferred.resolve(result);
+        fs.readFile(filePath, 'utf-8', (error, content) => {
+          if (error) {
+            deferred.reject(error);
+            return;
+          }
+
+          // Import the `package.json` of the project.
+          // Use `process.cdwd()`
+          const pkgPath = path.resolve(process.cwd(), 'package.json');
+          const pkg = require(pkgPath);
+
+          // Create the template function with lodash.
+          const tmpl = _.template(content);
+
+          // Generate the banner.
+          let banner = tmpl({_, moment, pkg});
+
+          // Make a block comment if needed
+          const trimmedBanner = banner.trim();
+          const start = trimmedBanner.slice(0, 3);
+          if (start !== '/**') {
+            const bannerContent = trimmedBanner
+              .split(`${EOL}`)
+              .map((line) => _.trimEnd(` * ${line}`))
+              .join(`${EOL}`);
+
+            banner = `/**${EOL}${bannerContent}${EOL} */${EOL}`;
+          }
+
+          // Create a magicString: do not manipulate the string directly since it
+          // will be used to generate the sourcemap.
+          const magicString = new MagicString(code);
+
+          // Prepend the banner.
+          magicString.prepend(`${banner}${EOL}`);
+
+          // Create the result object.
+          const result = {
+            code: magicString.toString(),
+          };
+
+          // Add sourceMap information if it is enabled.
+          if (options.sourceMap !== false) {
+            result.map = magicString.generateMap({
+              hires: true,
+            });
+          }
+
+          // Everything is ok.
+          deferred.resolve(result);
+        });
       });
 
       return deferred.promise;

test/index.spec.js

@@ -52,6 +52,21 @@ describe('rollup-plugin-license', () => {
     });
   });
 
+  it('should prepend default LICENSE file banner to bundle', (done) => {
+    const instance = plugin();
+
+    const code = 'var foo = 0;';
+
+    const promise = instance.transformBundle(code);
+
+    promise.then((result) => {
+      expect(result).toBeDefined();
+      expect(result.code).toBeDefined();
+      expect(result.code).toContain('The MIT License (MIT)');
+      done();
+    });
+  });
+
   it('should prepend banner and create block comment', (done) => {
     const instance = plugin({
       file: path.join(__dirname, 'fixtures', 'banner.txt'),