Added removePolicy and listPolicies methods to PolicyPipeline to allow for easier modification and inspection of the pipeline's policies. (#18)

* extend fetch request

Author: zmofei

src/utils/fetchRequest.ts

@@ -1,6 +1,7 @@
 import { getVersionInfo } from './versionUtils.js';
 
 export interface FetchPolicy {
+  id: string;
   handle(
     input: string | URL | Request,
     init: RequestInit,
@@ -16,10 +17,26 @@ export class PolicyPipeline {
     this.fetchImpl = fetchImpl ?? fetch;
   }
 
-  use(policy: FetchPolicy) {
+  usePolicy(policy: FetchPolicy) {
     this.policies.push(policy);
   }
 
+  removePolicy(policyOrId: FetchPolicy | string) {
+    if (typeof policyOrId === 'string') {
+      this.policies = this.policies.filter((p) => p.id !== policyOrId);
+    } else {
+      this.policies = this.policies.filter((p) => p !== policyOrId);
+    }
+  }
+
+  findPolicyById(id: string): FetchPolicy | undefined {
+    return this.policies.find((p) => p.id === id);
+  }
+
+  listPolicies() {
+    return this.policies;
+  }
+
   async fetch(
     input: string | URL | Request,
     init: RequestInit = {}
@@ -41,7 +58,16 @@ export class PolicyPipeline {
 }
 
 export class UserAgentPolicy implements FetchPolicy {
-  constructor(private userAgent: string) {}
+  id: string;
+
+  constructor(
+    private userAgent: string,
+    id?: string
+  ) {
+    this.id =
+      id ??
+      `user-agent-${Date.now()}-${Math.random().toString(36).substring(2, 11)}`;
+  }
   async handle(
     input: string | URL | Request,
     init: RequestInit,
@@ -65,24 +91,34 @@ export class UserAgentPolicy implements FetchPolicy {
     return next(input, { ...init, headers });
   }
 
-  static fromVersionInfo(versionInfo: {
-    name: string;
-    version: string;
-    sha: string;
-    tag: string;
-    branch: string;
-  }): UserAgentPolicy {
+  static fromVersionInfo(
+    versionInfo: {
+      name: string;
+      version: string;
+      sha: string;
+      tag: string;
+      branch: string;
+    },
+    id?: string
+  ): UserAgentPolicy {
     const userAgent = `${versionInfo.name}/${versionInfo.version} (${versionInfo.branch}, ${versionInfo.tag}, ${versionInfo.sha})`;
-    return new UserAgentPolicy(userAgent);
+    return new UserAgentPolicy(userAgent, id);
   }
 }
 
 export class RetryPolicy implements FetchPolicy {
+  id: string;
+
   constructor(
     private maxRetries: number = 3,
     private baseDelayMs: number = 200,
-    private maxDelayMs: number = 2000
-  ) {}
+    private maxDelayMs: number = 2000,
+    id?: string
+  ) {
+    this.id =
+      id ??
+      `retry-${Date.now()}-${Math.random().toString(36).substring(2, 11)}`;
+  }
 
   async handle(
     input: string | URL | Request,
@@ -119,7 +155,10 @@ export class RetryPolicy implements FetchPolicy {
 
 const pipeline = new PolicyPipeline();
 const versionInfo = getVersionInfo();
-pipeline.use(UserAgentPolicy.fromVersionInfo(versionInfo));
-pipeline.use(new RetryPolicy(3, 200, 2000));
+pipeline.usePolicy(
+  UserAgentPolicy.fromVersionInfo(versionInfo, 'system-user-agent-policy')
+);
+pipeline.usePolicy(new RetryPolicy(3, 200, 2000, 'system-retry-policy'));
 
 export const fetchClient = pipeline.fetch.bind(pipeline);
+export const systemFetchPipeline = pipeline;

test/utils/fetchRequest.test.ts

@@ -23,6 +23,72 @@ function createMockFetch(
 }
 
 describe('PolicyPipeline', () => {
+  describe('usePolicy, removePolicy, and listPolicies', () => {
+    it('adds policies with usePolicy', () => {
+      const pipeline = new PolicyPipeline();
+      const policy1 = new UserAgentPolicy('Agent1');
+      const policy2 = new RetryPolicy();
+
+      pipeline.usePolicy(policy1);
+      pipeline.usePolicy(policy2);
+
+      const policies = pipeline.listPolicies();
+      expect(policies).toHaveLength(2);
+      expect(policies[0]).toBe(policy1);
+      expect(policies[1]).toBe(policy2);
+    });
+
+    it('removes policies with removePolicy', () => {
+      const pipeline = new PolicyPipeline();
+      const policy1 = new UserAgentPolicy('Agent1');
+      const policy2 = new RetryPolicy();
+      const policy3 = new UserAgentPolicy('Agent3');
+
+      pipeline.usePolicy(policy1);
+      pipeline.usePolicy(policy2);
+      pipeline.usePolicy(policy3);
+
+      pipeline.removePolicy(policy2);
+
+      const policies = pipeline.listPolicies();
+      expect(policies).toHaveLength(2);
+      expect(policies[0]).toBe(policy1);
+      expect(policies[1]).toBe(policy3);
+    });
+
+    it('removePolicy does nothing if policy not found', () => {
+      const pipeline = new PolicyPipeline();
+      const policy1 = new UserAgentPolicy('Agent1');
+      const policy2 = new RetryPolicy();
+
+      pipeline.usePolicy(policy1);
+
+      pipeline.removePolicy(policy2); // Not in the list
+
+      const policies = pipeline.listPolicies();
+      expect(policies).toHaveLength(1);
+      expect(policies[0]).toBe(policy1);
+    });
+
+    it('listPolicies returns empty array initially', () => {
+      const pipeline = new PolicyPipeline();
+      expect(pipeline.listPolicies()).toEqual([]);
+    });
+
+    it('listPolicies returns the policies array', () => {
+      const pipeline = new PolicyPipeline();
+      const policy = new UserAgentPolicy('Agent1');
+
+      pipeline.usePolicy(policy);
+      const policies1 = pipeline.listPolicies();
+      const policies2 = pipeline.listPolicies();
+
+      expect(policies1).toBe(policies2); // Same reference
+      expect(policies1).toEqual(policies2); // Same content
+      expect(policies1).toContain(policy);
+    });
+  });
+
   describe('RetryPolicy', () => {
     afterEach(() => {
       vi.restoreAllMocks();
@@ -36,7 +102,7 @@ describe('PolicyPipeline', () => {
         { status: 500 }
       ]);
       const pipeline = new PolicyPipeline(mockFetch);
-      pipeline.use(new RetryPolicy(3, 1, 10)); // Use small delays for test speed
+      pipeline.usePolicy(new RetryPolicy(3, 1, 10)); // Use small delays for test speed
 
       const response = await pipeline.fetch('http://test', {});
 
@@ -51,7 +117,7 @@ describe('PolicyPipeline', () => {
         { status: 200, ok: true }
       ]);
       const pipeline = new PolicyPipeline(mockFetch);
-      pipeline.use(new RetryPolicy(3, 1, 10));
+      pipeline.usePolicy(new RetryPolicy(3, 1, 10));
 
       const response = await pipeline.fetch('http://test', {});
 
@@ -63,7 +129,7 @@ describe('PolicyPipeline', () => {
     it('does not retry on 400 errors', async () => {
       const mockFetch = createMockFetch([{ status: 400 }]);
       const pipeline = new PolicyPipeline(mockFetch);
-      pipeline.use(new RetryPolicy(3, 1, 10));
+      pipeline.usePolicy(new RetryPolicy(3, 1, 10));
 
       const response = await pipeline.fetch('http://test', {});
 
@@ -74,7 +140,7 @@ describe('PolicyPipeline', () => {
     it('returns immediately on first success', async () => {
       const mockFetch = createMockFetch([{ status: 200, ok: true }]);
       const pipeline = new PolicyPipeline(mockFetch);
-      pipeline.use(new RetryPolicy(3, 1, 10));
+      pipeline.usePolicy(new RetryPolicy(3, 1, 10));
 
       const response = await pipeline.fetch('http://test', {});
 
@@ -99,7 +165,7 @@ describe('PolicyPipeline', () => {
       ) as Mock;
 
       const pipeline = new PolicyPipeline(mockFetch as unknown as typeof fetch);
-      pipeline.use(new UserAgentPolicy('TestAgent/1.0'));
+      pipeline.usePolicy(new UserAgentPolicy('TestAgent/1.0'));
 
       await pipeline.fetch('http://test', {});
 
@@ -124,7 +190,7 @@ describe('PolicyPipeline', () => {
       ) as Mock;
 
       const pipeline = new PolicyPipeline(mockFetch as unknown as typeof fetch);
-      pipeline.use(new UserAgentPolicy('TestAgent/1.0'));
+      pipeline.usePolicy(new UserAgentPolicy('TestAgent/1.0'));
 
       await pipeline.fetch('http://test', {
         headers: {
@@ -153,12 +219,107 @@ describe('PolicyPipeline', () => {
       ) as Mock;
 
       const pipeline = new PolicyPipeline(mockFetch as unknown as typeof fetch);
-      pipeline.use(new UserAgentPolicy('TestAgent/1.0'));
+      pipeline.usePolicy(new UserAgentPolicy('TestAgent/1.0'));
 
       const headers = new Headers();
       await pipeline.fetch('http://test', { headers });
 
       expect(headers.get('User-Agent')).toBe('TestAgent/1.0');
     });
   });
+
+  describe('Policy ID functionality', () => {
+    it('assigns unique IDs to policies when not provided', () => {
+      const policy1 = new UserAgentPolicy('Agent1');
+      const policy2 = new UserAgentPolicy('Agent2');
+      const policy3 = new RetryPolicy();
+
+      expect(policy1.id).toBeDefined();
+      expect(policy2.id).toBeDefined();
+      expect(policy3.id).toBeDefined();
+      expect(policy1.id).not.toBe(policy2.id);
+      expect(policy2.id).not.toBe(policy3.id);
+    });
+
+    it('uses custom ID when provided', () => {
+      const customId = 'my-custom-policy';
+      const policy = new UserAgentPolicy('Agent1', customId);
+
+      expect(policy.id).toBe(customId);
+    });
+
+    it('removes policies by ID using removePolicy', () => {
+      const pipeline = new PolicyPipeline();
+      const policy1 = new UserAgentPolicy('Agent1', 'policy-1');
+      const policy2 = new RetryPolicy(3, 200, 2000, 'policy-2');
+      const policy3 = new UserAgentPolicy('Agent3', 'policy-3');
+
+      pipeline.usePolicy(policy1);
+      pipeline.usePolicy(policy2);
+      pipeline.usePolicy(policy3);
+
+      pipeline.removePolicy('policy-2'); // Remove by ID string
+
+      const policies = pipeline.listPolicies();
+      expect(policies).toHaveLength(2);
+      expect(policies[0]).toBe(policy1);
+      expect(policies[1]).toBe(policy3);
+    });
+
+    it('removePolicy supports both policy instance and ID string', () => {
+      const pipeline = new PolicyPipeline();
+      const policy1 = new UserAgentPolicy('Agent1', 'policy-1');
+      const policy2 = new RetryPolicy(3, 200, 2000, 'policy-2');
+      const policy3 = new UserAgentPolicy('Agent3', 'policy-3');
+      const policy4 = new UserAgentPolicy('Agent4', 'policy-4');
+
+      pipeline.usePolicy(policy1);
+      pipeline.usePolicy(policy2);
+      pipeline.usePolicy(policy3);
+      pipeline.usePolicy(policy4);
+
+      // Remove by policy instance
+      pipeline.removePolicy(policy2);
+
+      // Remove by ID string
+      pipeline.removePolicy('policy-4');
+
+      const policies = pipeline.listPolicies();
+      expect(policies).toHaveLength(2);
+      expect(policies[0]).toBe(policy1);
+      expect(policies[1]).toBe(policy3);
+    });
+
+    it('finds policies by ID', () => {
+      const pipeline = new PolicyPipeline();
+      const policy1 = new UserAgentPolicy('Agent1', 'policy-1');
+      const policy2 = new RetryPolicy(3, 200, 2000, 'policy-2');
+
+      pipeline.usePolicy(policy1);
+      pipeline.usePolicy(policy2);
+
+      expect(pipeline.findPolicyById('policy-1')).toBe(policy1);
+      expect(pipeline.findPolicyById('policy-2')).toBe(policy2);
+      expect(pipeline.findPolicyById('non-existent')).toBeUndefined();
+    });
+
+    it('fromVersionInfo accepts optional ID parameter', () => {
+      const versionInfo = {
+        name: 'test-app',
+        version: '1.0.0',
+        sha: 'abc123',
+        tag: 'v1.0.0',
+        branch: 'main'
+      };
+
+      const policyWithoutId = UserAgentPolicy.fromVersionInfo(versionInfo);
+      const policyWithId = UserAgentPolicy.fromVersionInfo(
+        versionInfo,
+        'custom-id'
+      );
+
+      expect(policyWithoutId.id).toBeDefined();
+      expect(policyWithId.id).toBe('custom-id');
+    });
+  });
 });

test/utils/fetchRequestUtils.ts

@@ -19,7 +19,7 @@ export function setupFetch(overrides?: any) {
   // Build a real pipeline with UserAgentPolicy
   const userAgent = 'TestServer/1.0.0 (default, no-tag, abcdef)';
   const pipeline = new PolicyPipeline(mockFetch);
-  pipeline.use(new UserAgentPolicy(userAgent));
+  pipeline.usePolicy(new UserAgentPolicy(userAgent));
 
   return { fetch: pipeline.fetch.bind(pipeline), mockFetch };
 }