fix: use whatBump option

index.js

@@ -48,6 +48,8 @@ class ConventionalChangelog extends Plugin {
       async function getWhatBump() {
         if (options.whatBump === false) {
           return () => ({ releaseType: null });
+        } else if (typeof options.whatBump === 'function') {
+          return options.whatBump;
         }
         const bumperPreset = await bumper.preset;
 

test.js

@@ -1,4 +1,4 @@
-import test from 'node:test';
+import {mock, test} from 'node:test';
 import { strict as assert } from 'assert';
 import fs from 'fs';
 import path from 'path';
@@ -382,6 +382,21 @@ test('should not bump when whatBump === false', async () => {
   }
 });
 
+test('should use given whatBump when provided',  async () => {
+  setup();
+  sh.exec(`git tag 1.0.0`);
+  add('fix', 'bar');
+  const whatBump = mock.fn()
+  {
+    const options = getOptions({ whatBump });
+    await runTasks(...options);
+    assert.ok(whatBump.mock.callCount() > 1)
+    const commitHeaders = whatBump.mock.calls[0].arguments[0]?.map((commit) => commit.header)
+    assert.strictEqual(commitHeaders.length, 1)
+    assert.match(commitHeaders[0], /^fix\(bar\):/)
+  }
+});
+
 // TODO Prepare test and verify results influenced by parserOpts and writerOpts
 test.skip('should pass parserOpts and writerOpts', async t => {
   setup();