fix(migration): throw error for invalid hostRules

lib/config/migration.spec.ts

@@ -20,7 +20,6 @@ describe('config/migration', () => {
           {
             platform: 'docker',
             endpoint: 'https://docker.io',
-            host: 'docker.io',
             username: 'some-username',
             password: 'some-password',
           },

lib/config/migrations/custom/host-rules-migration.spec.ts

@@ -1,3 +1,4 @@
+import { CONFIG_VALIDATION } from '../../../constants/error-messages';
 import { HostRulesMigration } from './host-rules-migration';
 
 describe('config/migrations/custom/host-rules-migration', () => {
@@ -18,6 +19,8 @@ describe('config/migrations/custom/host-rules-migration', () => {
           { domainName: 'domain.com/', token: '123test' },
           { hostType: 'docker', matchHost: 'domain.com/', token: '123test' },
           { hostName: 'some.domain.com', token: '123test' },
+          { endpoint: 'domain.com/', token: '123test' },
+          { host: 'some.domain.com', token: '123test' },
         ],
       } as any,
       {
@@ -42,8 +45,33 @@ describe('config/migrations/custom/host-rules-migration', () => {
             token: '123test',
           },
           { matchHost: 'some.domain.com', token: '123test' },
+          { matchHost: 'https://domain.com/', token: '123test' },
+          { matchHost: 'some.domain.com', token: '123test' },
         ],
       }
     );
   });
+
+  it('throws when multiple hosts are present', () => {
+    expect(() =>
+      new HostRulesMigration(
+        {
+          hostRules: [
+            {
+              matchHost: 'https://some.domain.com',
+              baseUrl: 'https://some.domain.com',
+              token: '123test',
+            },
+          ],
+        } as any,
+        {}
+      ).run([
+        {
+          matchHost: 'https://some.domain.com',
+          baseUrl: 'https://some.domain.com',
+          token: '123test',
+        },
+      ])
+    ).toThrow(CONFIG_VALIDATION);
+  });
 });

lib/config/migrations/custom/host-rules-migration.ts

@@ -1,14 +1,18 @@
 import is from '@sindresorhus/is';
+import { CONFIG_VALIDATION } from '../../../constants/error-messages';
 import type { HostRule } from '../../../types';
+import type { LegacyHostRule } from '../../../util/host-rules';
 import { AbstractMigration } from '../base/abstract-migration';
 import { migrateDatasource } from './datasource-migration';
 
 export class HostRulesMigration extends AbstractMigration {
   override readonly propertyName = 'hostRules';
 
-  override run(value: Record<string, unknown>[]): void {
+  override run(value: (LegacyHostRule & HostRule)[]): void {
     const newHostRules: HostRule[] = [];
     for (const hostRule of value) {
+      validateHostRule(hostRule);
+
       const newRule: any = {};
 
       for (const [key, value] of Object.entries(hostRule)) {
@@ -56,6 +60,27 @@ export class HostRulesMigration extends AbstractMigration {
   }
 }
 
+function validateHostRule(rule: LegacyHostRule & HostRule): void {
+  const { matchHost } = rule;
+  const { hostName, domainName, baseUrl, endpoint, host } = rule;
+  const hostValues = [
+    matchHost,
+    hostName,
+    domainName,
+    baseUrl,
+    endpoint,
+    host,
+  ].filter(is.string);
+  if (hostValues.length > 1) {
+    const error = new Error(CONFIG_VALIDATION);
+    error.validationSource = 'config';
+    error.validationMessage = `hostRules cannot contain more than one host-matching field - use "matchHost" only.`;
+    error.validationError =
+      'The renovate configuration file contains some invalid settings';
+    throw error;
+  }
+}
+
 function massageUrl(url: string): string {
   if (!url.includes('://') && url.includes('/')) {
     return 'https://' + url;

lib/util/host-rules.ts

@@ -9,13 +9,15 @@ import { parseUrl, validateUrl } from './url';
 
 let hostRules: HostRule[] = [];
 
-interface LegacyHostRule {
+export interface LegacyHostRule {
   hostName?: string;
   domainName?: string;
   baseUrl?: string;
+  host?: string;
+  endpoint?: string;
 }
 
-function migrateRule(rule: LegacyHostRule & HostRule): HostRule {
+export function migrateRule(rule: LegacyHostRule & HostRule): HostRule {
   const cloned: LegacyHostRule & HostRule = clone(rule);
   delete cloned.hostName;
   delete cloned.domainName;