Refactor changelog out of changes

Author: mantoni

lib/changelog.js

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) Maximilian Antoni <max@javascript.studio>
+ *
+ * @license MIT
+ */
+'use strict';
+
+const $ = require('child_process');
+
+const VARIABLE_RE = /\$\{([^}]+)\}/g;
+
+function parseAuthor(author) {
+  const m = author.match(/[<(]/);
+  return m ? author.substring(0, m.index).trim() : author;
+}
+
+module.exports = function ({
+  log_range,
+  commits,
+  newline,
+  pkg
+}) {
+
+  let flags = '--format="» ';
+  if (commits) {
+    commits = commits.replace(VARIABLE_RE, (match, key) => pkg[key]);
+    flags += `[\\\`%h\\\`](${commits}/%H)«  `;
+  }
+  flags += '%s (%an)%n%n%b" --no-merges';
+  let changes;
+  try {
+    changes = $.execSync(`git log ${log_range} ${flags}`, {
+      encoding: 'utf8'
+    });
+  } catch (e) {
+    process.exit(1);
+    return null;
+  }
+  // Remove blanks (if no body) and indent body
+  changes = changes
+    .replace(/\n{3,}/g, '\n')
+    // Indent body with quotes:
+    .replace(/^([^»])/gm, '    > $1')
+    // Remove trainling whitespace on blank quote lines
+    .replace(/^ {4}> \n/gm, '    >\n');
+
+  changes = changes
+    // Replace commit markers with dashes:
+    .replace(/^»/gm, '-')
+    // Replace newline markers with newlines:
+    .replace(/«/gm, '\n')
+    // Restore original newlines:
+    .replace(/\n/gm, newline);
+
+  // Only mention contributors
+  const { author } = pkg;
+  if (author) {
+    const author_name = typeof author === 'object'
+      ? author.name
+      : parseAuthor(author);
+    changes = changes.replace(new RegExp(` \\(${author_name}\\)$`, 'gm'), '');
+  }
+
+  return changes;
+};

lib/changes.js

@@ -7,6 +7,7 @@
 
 const fs = require('fs');
 const $ = require('child_process');
+const changelog = require('./changelog');
 
 const CHANGES_HEADING = '# Changes';
 const DEFAULT_CHANGES_FILE = 'CHANGES.md';
@@ -27,11 +28,6 @@ function buildTag(options, version, pkg) {
   );
 }
 
-function parseAuthor(author) {
-  const m = author.match(/[<(]/);
-  return m ? author.substring(0, m.index).trim() : author;
-}
-
 // Write the commit history to the changes file
 exports.write = function (options, callback) {
   if (typeof options === 'function') {
@@ -45,10 +41,11 @@ exports.write = function (options, callback) {
       callback = () => {};
     }
   }
+
   const changes_file = options.changes_file || DEFAULT_CHANGES_FILE;
   const package_json = fs.readFileSync('package.json', 'utf8');
   const pkg = JSON.parse(package_json);
-  const { version, author } = pkg;
+  const { version } = pkg;
 
   // Get previous file content
   let previous;
@@ -75,7 +72,7 @@ exports.write = function (options, callback) {
   if (version_match) {
     log_range = `${buildTag(options, version_match[1], pkg)}..HEAD`;
   }
-  let flags = '--format="» ';
+
   let commits = options.commits;
   if (commits) {
     if (commits === true) {
@@ -87,42 +84,14 @@ exports.write = function (options, callback) {
         return;
       }
     }
-    commits = commits.replace(VARIABLE_RE, (match, key) => pkg[key]);
-    flags += `[\\\`%h\\\`](${commits}/%H)«  `;
-  }
-  flags += '%s (%an)%n%n%b" --no-merges';
-  let changes;
-  try {
-    changes = $.execSync(`git log ${log_range} ${flags}`, {
-      encoding: 'utf8'
-    });
-  } catch (e) {
-    process.exit(1);
-    return;
   }
-  // Remove blanks (if no body) and indent body
-  changes = changes
-    .replace(/\n{3,}/g, '\n')
-    // Indent body with quotes:
-    .replace(/^([^»])/gm, '    > $1')
-    // Remove trainling whitespace on blank quote lines
-    .replace(/^ {4}> \n/gm, '    >\n');
 
-  changes = changes
-    // Replace commit markers with dashes:
-    .replace(/^»/gm, '-')
-    // Replace newline markers with newlines:
-    .replace(/«/gm, '\n')
-    // Restore original newlines:
-    .replace(/\n/gm, newline);
-
-  // Only mention contributors
-  if (author) {
-    const author_name = typeof author === 'object'
-      ? author.name
-      : parseAuthor(author);
-    changes = changes.replace(new RegExp(` \\(${author_name}\\)$`, 'gm'), '');
-  }
+  const changes = changelog({
+    log_range,
+    commits,
+    newline,
+    pkg
+  });
 
   // Do not allow version to be added twice
   if (exists(previous, version)) {
@@ -142,6 +111,7 @@ exports.write = function (options, callback) {
     next += `${newline}${remain}`;
   }
   fs.writeFileSync(changes_file, next);
+
   callback(null, { previous, changes_file });
 };