refactor: migration semantic prefix

lib/config/migration.ts

@@ -105,16 +105,6 @@ export function migrateConfig(config: RenovateConfig): MigratedConfig {
           regEx(/{{depNameShort}}/g),
           '{{depName}}'
         );
-      } else if (key === 'semanticPrefix' && is.string(val)) {
-        delete migratedConfig.semanticPrefix;
-        let [text] = val.split(':') as any; // TODO: fixme
-        text = text.split('(');
-        [migratedConfig.semanticCommitType] = text;
-        if (text.length > 1) {
-          [migratedConfig.semanticCommitScope] = text[1].split(')');
-        } else {
-          migratedConfig.semanticCommitScope = null;
-        }
       } else if (is.string(val) && val.startsWith('{{semanticPrefix}}')) {
         migratedConfig[key] = val.replace(
           '{{semanticPrefix}}',

lib/config/migrations/custom/semantic-prefix-migration.spec.ts

@@ -0,0 +1,39 @@
+import { SemanticPrefixMigration } from './semantic-prefix-migration';
+
+describe('config/migrations/custom/semantic-prefix-migration', () => {
+  it('should work', () => {
+    expect(SemanticPrefixMigration).toMigrate(
+      {
+        semanticPrefix: 'fix(deps): ',
+      } as any,
+      { semanticCommitType: 'fix', semanticCommitScope: 'deps' }
+    );
+  });
+
+  it('should remove non-string values', () => {
+    expect(SemanticPrefixMigration).toMigrate(
+      {
+        semanticPrefix: true,
+      } as any,
+      {}
+    );
+  });
+
+  it('should migrate prefix with no-scope to null', () => {
+    expect(SemanticPrefixMigration).toMigrate(
+      {
+        semanticPrefix: 'fix: ',
+      } as any,
+      { semanticCommitType: 'fix', semanticCommitScope: null }
+    );
+  });
+
+  it('works for random string', () => {
+    expect(SemanticPrefixMigration).toMigrate(
+      {
+        semanticPrefix: 'test',
+      } as any,
+      { semanticCommitType: 'test', semanticCommitScope: null }
+    );
+  });
+});

lib/config/migrations/custom/semantic-prefix-migration.ts

@@ -0,0 +1,16 @@
+import is from '@sindresorhus/is';
+import { AbstractMigration } from '../base/abstract-migration';
+
+export class SemanticPrefixMigration extends AbstractMigration {
+  override readonly deprecated = true;
+  override readonly propertyName = 'semanticPrefix';
+
+  override run(value: unknown): void {
+    if (is.string(value)) {
+      const [text] = value.split(':');
+      const [type, scope] = text.split('(');
+      this.setSafely('semanticCommitType', type);
+      this.setSafely('semanticCommitScope', scope ? scope.split(')')[0] : null);
+    }
+  }
+}

lib/config/migrations/migrations-service.ts

@@ -37,6 +37,7 @@ import { RequireConfigMigration } from './custom/require-config-migration';
 import { RequiredStatusChecksMigration } from './custom/required-status-checks-migration';
 import { ScheduleMigration } from './custom/schedule-migration';
 import { SemanticCommitsMigration } from './custom/semantic-commits-migration';
+import { SemanticPrefixMigration } from './custom/semantic-prefix-migration';
 import { SeparateMajorReleasesMigration } from './custom/separate-major-release-migration';
 import { SeparateMultipleMajorMigration } from './custom/separate-multiple-major-migration';
 import { SuppressNotificationsMigration } from './custom/suppress-notifications-migration';
@@ -119,6 +120,7 @@ export class MigrationsService {
     VersionStrategyMigration,
     DryRunMigration,
     RequireConfigMigration,
+    SemanticPrefixMigration,
   ];
 
   static run(originalConfig: RenovateConfig): RenovateConfig {