Shorten CHANGELOGs

Signed-off-by: Tim Hansen <timbonicus@gmail.com>

.changeset/backstage-changelog.js

@@ -0,0 +1,38 @@
+/*
+ * Copyright 2021 Spotify AB
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+const {
+  default: defaultChangelogFunctions,
+} = require('@changesets/cli/changelog');
+
+// Custom CHANGELOG generation for changesets, stolen from here with one minor change:
+// https://github.com/atlassian/changesets/blob/main/packages/cli/src/changelog/index.ts
+async function getDependencyReleaseLine(changesets, dependenciesUpdated) {
+  if (dependenciesUpdated.length === 0) return '';
+
+  const updatedDepenenciesList = dependenciesUpdated.map(
+    dependency => `  - ${dependency.name}@${dependency.newVersion}`,
+  );
+
+  // Return one `Updated dependencies` bullet instead of repeating for each changeset; this
+  // sacrifices the commit shas for brevity.
+  return ['- Updated dependencies', ...updatedDepenenciesList].join('\n');
+}
+
+module.exports = {
+  getReleaseLine: defaultChangelogFunctions.getReleaseLine,
+  getDependencyReleaseLine,
+};

.changeset/config.json

@@ -1,6 +1,6 @@
 {
   "$schema": "https://unpkg.com/@changesets/config@1.3.0/schema.json",
-  "changelog": "@changesets/cli/changelog",
+  "changelog": "./backstage-changelog.js",
   "commit": false,
   "linked": [["*"]],
   "access": "public",