Fix isIncrement to return only the version requested

index.js

@@ -53,37 +53,48 @@ class KeepAChangelog extends Plugin {
   }
 
   getChangelog(latestVersion) {
-    const { isIncrement } = this.config;
-    // Return the unchanged changelog content when no increment is made
-    if (!isIncrement) {
-      return this.changelogContent;
-    }
-
     const { changelog } = this.getContext();
     if (changelog) return changelog;
 
     const { filename, strictLatest } = this;
-
     const previousReleaseTitle = strictLatest ? `## [${latestVersion}]` : `## [`;
     const hasPreviousReleaseSection = this.changelogContent.includes(previousReleaseTitle);
-
     if (strictLatest && !hasPreviousReleaseSection) {
       throw Error(`Missing section for previous release ("${latestVersion}") in ${filename}.`);
     }
 
-    const startIndex = this.changelogContent.indexOf(this.unreleasedTitle) + this.unreleasedTitle.length;
-    let endIndex = this.changelogContent.indexOf(previousReleaseTitle, startIndex);
-    if (!strictLatest && endIndex === -1) {
-      endIndex = this.changelogContent.length;
+    const { isIncrement } = this.config;
+    const titleToFind = isIncrement ? this.unreleasedTitleRaw : latestVersion;
+    const changelogContent = this.getChangelogEntryContent(titleToFind);
+
+    this.setContext({ changelog: changelogContent });
+    return changelogContent;
+  }
+
+  getChangelogEntryContent(releaseTitleRaw) {
+    const { filename, changelogContent, EOL } = this;
+
+    const releaseTitleMarkdown = `## [${releaseTitleRaw}]`;
+    const previousReleaseTitle = `## [`;
+
+    const indexOfReleaseTitle = changelogContent.indexOf(releaseTitleMarkdown);
+
+    if (indexOfReleaseTitle === -1) {
+      throw Error(`Missing section for previous release ("${releaseTitleRaw}") in ${filename}.`);
+    }
+
+    const entryContentStartIndex = changelogContent.indexOf(EOL, indexOfReleaseTitle);
+    let entryContentEndIndex = changelogContent.indexOf(previousReleaseTitle, entryContentStartIndex);
+    if (entryContentEndIndex === -1) {
+      entryContentEndIndex = changelogContent.length;
     }
 
-    const changelogContent = this.changelogContent.substring(startIndex, endIndex).trim();
-    if (!changelogContent) {
-      throw Error(`There are no entries under "${this.unreleasedTitleRaw}" section in ${filename}.`);
+    const changelogEntryContent = changelogContent.substring(entryContentStartIndex, entryContentEndIndex).trim();
+    if (!changelogEntryContent) {
+      throw Error(`There are no entries under "${releaseTitleRaw}" section in ${filename}.`);
     }
 
-    this.setContext({ changelog: changelogContent });
-    return changelogContent;
+    return changelogEntryContent;
   }
 
   bump(version) {

test.js

@@ -1,9 +1,9 @@
-import fs from 'fs';
-import test from 'bron';
 import { strict as assert } from 'assert';
+import test from 'bron';
+import fs from 'fs';
 import mock from 'mock-fs';
+import { factory, runTasks } from 'release-it/test/util/index.js';
 import sinon from 'sinon';
-import { factory, runTasks } from 'release-it/test/util';
 import Plugin from './index.js';
 
 const initialDryRunFileContents =
@@ -56,11 +56,30 @@ test('should throw for empty "unreleased" section', async t => {
   await assert.rejects(runTasks(plugin), /There are no entries under "Unreleased" section in CHANGELOG-EMPTY\.md/);
 });
 
-test('should not throw for empty "unreleased" section when no-increment flag is set', async t => {
+test('should throw for missing "unreleased" section when no-increment flag is set if changelog is misformatted', async t => {
+  const options = { increment: false, [namespace]: { filename: 'CHANGELOG-FOO.md' } };
+  const plugin = factory(Plugin, { namespace, options });
+  await assert.rejects(runTasks(plugin), /Missing "Unreleased" section in CHANGELOG-FOO.md/);
+});
+
+test('should throw for missing "1.0.0" section when no-increment flag is set', async t => {
+  const options = { increment: false, [namespace]: { filename: 'CHANGELOG-MISSING.md' } };
+  const plugin = factory(Plugin, { namespace, options });
+  await assert.rejects(runTasks(plugin), /Missing section for previous release \("1\.0\.0"\) in CHANGELOG-MISSING\.md/);
+});
+
+test('should find "1.0.0" section when no-increment flag is set when items under version', async t => {
   const options = { increment: false, [namespace]: { filename: 'CHANGELOG-EMPTY.md' } };
   const plugin = factory(Plugin, { namespace, options });
   await runTasks(plugin);
-  assert.equal(plugin.getChangelog(), readFile('./CHANGELOG-EMPTY.md'));
+  assert.equal(plugin.getChangelog('1.0.0'), '* Item A\n* Item B');
+});
+
+test('should find "1.0.0" section when no-increment flag is set when items under unreleased and version', async t => {
+  const options = { increment: false, [namespace]: { filename: 'CHANGELOG-FULL.md' } };
+  const plugin = factory(Plugin, { namespace, options });
+  await runTasks(plugin);
+  assert.equal(plugin.getChangelog('1.0.0'), '* Item C\n* Item D');
 });
 
 test('should throw for missing section for previous release', async t => {