refactor: simplify mode system by removing Mode interface and registry (#899)

Replace the over-engineered Mode interface/registry/detector pattern with
straightforward inline logic. There are only 2 modes (tag and agent) and
the complexity wasn't justified.

- Delete Mode interface, registry, and prepare pass-through modules
- Export prepareTagMode() and prepareAgentMode() as standalone functions
- Inline trigger checking and mode dispatch in run.ts/prepare.ts
- Change generatePrompt/createPrompt to take modeName string instead of Mode
- Remove dead code (extractGitHubContext, unused detector helpers)
- Update CLAUDE.md to reflect new architecture

test/create-prompt.test.ts

@@ -3,60 +3,13 @@
 import { describe, test, expect } from "bun:test";
 import {
   generatePrompt,
-  generateDefaultPrompt,
   getEventTypeAndContext,
   buildAllowedToolsString,
   buildDisallowedToolsString,
 } from "../src/create-prompt";
 import type { PreparedContext } from "../src/create-prompt";
-import type { Mode } from "../src/modes/types";
 
 describe("generatePrompt", () => {
-  // Create a mock tag mode that uses the default prompt
-  const mockTagMode: Mode = {
-    name: "tag",
-    description: "Tag mode",
-    shouldTrigger: () => true,
-    prepareContext: (context) => ({ mode: "tag", githubContext: context }),
-    getAllowedTools: () => [],
-    getDisallowedTools: () => [],
-    shouldCreateTrackingComment: () => true,
-    generatePrompt: (context, githubData, useCommitSigning) =>
-      generateDefaultPrompt(context, githubData, useCommitSigning),
-    prepare: async () => ({
-      commentId: 123,
-      branchInfo: {
-        baseBranch: "main",
-        currentBranch: "main",
-        claudeBranch: undefined,
-      },
-      mcpConfig: "{}",
-      claudeArgs: "",
-    }),
-  };
-
-  // Create a mock agent mode that passes through prompts
-  const mockAgentMode: Mode = {
-    name: "agent",
-    description: "Agent mode",
-    shouldTrigger: () => true,
-    prepareContext: (context) => ({ mode: "agent", githubContext: context }),
-    getAllowedTools: () => [],
-    getDisallowedTools: () => [],
-    shouldCreateTrackingComment: () => false,
-    generatePrompt: (context) => context.prompt || "",
-    prepare: async () => ({
-      commentId: undefined,
-      branchInfo: {
-        baseBranch: "main",
-        currentBranch: "main",
-        claudeBranch: undefined,
-      },
-      mcpConfig: "{}",
-      claudeArgs: "",
-    }),
-  };
-
   const mockGitHubData = {
     contextData: {
       title: "Test PR",
@@ -181,12 +134,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     expect(prompt).toContain("You are Claude, an AI assistant");
     expect(prompt).toContain("<event_type>GENERAL_COMMENT</event_type>");
@@ -214,12 +162,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     expect(prompt).toContain("<event_type>PR_REVIEW</event_type>");
     expect(prompt).toContain("<is_pr>true</is_pr>");
@@ -245,12 +188,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     expect(prompt).toContain("<event_type>ISSUE_CREATED</event_type>");
     expect(prompt).toContain(
@@ -278,12 +216,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     expect(prompt).toContain("<event_type>ISSUE_ASSIGNED</event_type>");
     expect(prompt).toContain(
@@ -310,12 +243,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     expect(prompt).toContain("<event_type>ISSUE_LABELED</event_type>");
     expect(prompt).toContain(
@@ -341,12 +269,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     expect(prompt).toContain("<event_type>PULL_REQUEST</event_type>");
     expect(prompt).toContain("<is_pr>true</is_pr>");
@@ -370,12 +293,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Verify prompt generates successfully without custom instructions
     expect(prompt).toContain("@claude please fix this");
@@ -400,7 +318,7 @@ describe("generatePrompt", () => {
       envVars,
       mockGitHubData,
       false,
-      mockAgentMode,
+      "agent",
     );
 
     // Agent mode: Prompt is passed through as-is
@@ -441,7 +359,7 @@ describe("generatePrompt", () => {
       envVars,
       mockGitHubData,
       false,
-      mockAgentMode,
+      "agent",
     );
 
     // v1.0: Variables are NOT substituted - prompt is passed as-is to Claude Code
@@ -490,7 +408,7 @@ describe("generatePrompt", () => {
       envVars,
       issueGitHubData,
       false,
-      mockAgentMode,
+      "agent",
     );
 
     // Agent mode: Prompt is passed through as-is
@@ -515,7 +433,7 @@ describe("generatePrompt", () => {
       envVars,
       mockGitHubData,
       false,
-      mockAgentMode,
+      "agent",
     );
 
     // Agent mode: No substitution - passed as-is
@@ -539,12 +457,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     expect(prompt).toContain("You are Claude, an AI assistant");
     expect(prompt).toContain("<event_type>ISSUE_CREATED</event_type>");
@@ -567,12 +480,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     expect(prompt).toContain("<trigger_username>johndoe</trigger_username>");
     // With commit signing disabled, co-author info appears in git commit instructions
@@ -594,12 +502,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should contain PR-specific instructions (git commands when not using signing)
     expect(prompt).toContain("git push");
@@ -630,12 +533,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should contain Issue-specific instructions
     expect(prompt).toContain(
@@ -674,12 +572,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should contain the actual branch name with timestamp
     expect(prompt).toContain(
@@ -709,12 +602,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should contain branch-specific instructions like issues
     expect(prompt).toContain(
@@ -752,12 +640,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should contain open PR instructions (git commands when not using signing)
     expect(prompt).toContain("git push");
@@ -788,12 +671,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should contain new branch instructions
     expect(prompt).toContain(
@@ -821,12 +699,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should contain new branch instructions
     expect(prompt).toContain(
@@ -854,12 +727,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should contain new branch instructions
     expect(prompt).toContain(
@@ -883,12 +751,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      false,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, false, "tag");
 
     // Should have git command instructions
     expect(prompt).toContain("Use git commands via the Bash tool");
@@ -917,12 +780,7 @@ describe("generatePrompt", () => {
       },
     };
 
-    const prompt = await generatePrompt(
-      envVars,
-      mockGitHubData,
-      true,
-      mockTagMode,
-    );
+    const prompt = await generatePrompt(envVars, mockGitHubData, true, "tag");
 
     // Should have commit signing tool instructions
     expect(prompt).toContain("mcp__github_file_ops__commit_files");

test/modes/agent.test.ts

@@ -7,22 +7,17 @@ import {
   spyOn,
   mock,
 } from "bun:test";
-import { agentMode } from "../../src/modes/agent";
-import type { GitHubContext } from "../../src/github/context";
-import { createMockContext, createMockAutomationContext } from "../mockContext";
+import { prepareAgentMode } from "../../src/modes/agent";
+import { createMockAutomationContext } from "../mockContext";
 import * as core from "@actions/core";
 import * as gitConfig from "../../src/github/operations/git-config";
 
 describe("Agent Mode", () => {
-  let mockContext: GitHubContext;
   let exportVariableSpy: any;
   let setOutputSpy: any;
   let configureGitAuthSpy: any;
 
   beforeEach(() => {
-    mockContext = createMockAutomationContext({
-      eventName: "workflow_dispatch",
-    });
     exportVariableSpy = spyOn(core, "exportVariable").mockImplementation(
       () => {},
     );
@@ -45,84 +40,11 @@ describe("Agent Mode", () => {
     configureGitAuthSpy?.mockRestore();
   });
 
-  test("agent mode has correct properties", () => {
-    expect(agentMode.name).toBe("agent");
-    expect(agentMode.description).toBe(
-      "Direct automation mode for explicit prompts",
-    );
-    expect(agentMode.shouldCreateTrackingComment()).toBe(false);
-    expect(agentMode.getAllowedTools()).toEqual([]);
-    expect(agentMode.getDisallowedTools()).toEqual([]);
+  test("prepareAgentMode is exported as a function", () => {
+    expect(typeof prepareAgentMode).toBe("function");
   });
 
-  test("prepareContext returns minimal data", () => {
-    const context = agentMode.prepareContext(mockContext);
-
-    expect(context.mode).toBe("agent");
-    expect(context.githubContext).toBe(mockContext);
-    // Agent mode doesn't use comment tracking or branch management
-    expect(Object.keys(context)).toEqual(["mode", "githubContext"]);
-  });
-
-  test("agent mode only triggers when prompt is provided", () => {
-    // Should NOT trigger for automation events without prompt
-    const workflowDispatchContext = createMockAutomationContext({
-      eventName: "workflow_dispatch",
-    });
-    expect(agentMode.shouldTrigger(workflowDispatchContext)).toBe(false);
-
-    const scheduleContext = createMockAutomationContext({
-      eventName: "schedule",
-    });
-    expect(agentMode.shouldTrigger(scheduleContext)).toBe(false);
-
-    const repositoryDispatchContext = createMockAutomationContext({
-      eventName: "repository_dispatch",
-    });
-    expect(agentMode.shouldTrigger(repositoryDispatchContext)).toBe(false);
-
-    // Should NOT trigger for entity events without prompt
-    const entityEvents = [
-      "issue_comment",
-      "pull_request",
-      "pull_request_review",
-      "issues",
-    ] as const;
-
-    entityEvents.forEach((eventName) => {
-      const contextNoPrompt = createMockContext({ eventName });
-      expect(agentMode.shouldTrigger(contextNoPrompt)).toBe(false);
-    });
-
-    // Should trigger for ANY event when prompt is provided
-    const allEvents = [
-      "workflow_dispatch",
-      "repository_dispatch",
-      "schedule",
-      "issue_comment",
-      "pull_request",
-      "pull_request_review",
-      "issues",
-    ] as const;
-
-    allEvents.forEach((eventName) => {
-      const contextWithPrompt =
-        eventName === "workflow_dispatch" ||
-        eventName === "repository_dispatch" ||
-        eventName === "schedule"
-          ? createMockAutomationContext({
-              eventName,
-              inputs: { prompt: "Do something" },
-            })
-          : createMockContext({
-              eventName,
-              inputs: { prompt: "Do something" },
-            });
-      expect(agentMode.shouldTrigger(contextWithPrompt)).toBe(true);
-    });
-  });
-
-  test("prepare method passes through claude_args", async () => {
+  test("prepare passes through claude_args", async () => {
     // Clear any previous calls before this test
     exportVariableSpy.mockClear();
     setOutputSpy.mockClear();
@@ -156,7 +78,7 @@ describe("Agent Mode", () => {
         },
       },
     } as any;
-    const result = await agentMode.prepare({
+    const result = await prepareAgentMode({
       context: contextWithCustomArgs,
       octokit: mockOctokit,
       githubToken: "test-token",
@@ -186,7 +108,7 @@ describe("Agent Mode", () => {
       process.env.GITHUB_REF_NAME = originalRefName;
   });
 
-  test("prepare method rejects bot actors without allowed_bots", async () => {
+  test("prepare rejects bot actors without allowed_bots", async () => {
     const contextWithPrompts = createMockAutomationContext({
       eventName: "workflow_dispatch",
     });
@@ -206,7 +128,7 @@ describe("Agent Mode", () => {
     } as any;
 
     await expect(
-      agentMode.prepare({
+      prepareAgentMode({
         context: contextWithPrompts,
         octokit: mockOctokit,
         githubToken: "test-token",
@@ -216,7 +138,7 @@ describe("Agent Mode", () => {
     );
   });
 
-  test("prepare method allows bot actors when in allowed_bots list", async () => {
+  test("prepare allows bot actors when in allowed_bots list", async () => {
     const contextWithPrompts = createMockAutomationContext({
       eventName: "workflow_dispatch",
     });
@@ -237,7 +159,7 @@ describe("Agent Mode", () => {
 
     // Should not throw - bot is in allowed list
     await expect(
-      agentMode.prepare({
+      prepareAgentMode({
         context: contextWithPrompts,
         octokit: mockOctokit,
         githubToken: "test-token",
@@ -245,7 +167,7 @@ describe("Agent Mode", () => {
     ).resolves.toBeDefined();
   });
 
-  test("prepare method creates prompt file with correct content", async () => {
+  test("prepare creates prompt file with correct content", async () => {
     const contextWithPrompts = createMockAutomationContext({
       eventName: "workflow_dispatch",
     });
@@ -268,7 +190,7 @@ describe("Agent Mode", () => {
         },
       },
     } as any;
-    const result = await agentMode.prepare({
+    const result = await prepareAgentMode({
       context: contextWithPrompts,
       octokit: mockOctokit,
       githubToken: "test-token",

test/modes/registry.test.ts

@@ -1,155 +0,0 @@
-import { describe, test, expect } from "bun:test";
-import { getMode, isValidMode } from "../../src/modes/registry";
-import { agentMode } from "../../src/modes/agent";
-import { tagMode } from "../../src/modes/tag";
-import {
-  createMockContext,
-  createMockAutomationContext,
-  mockRepositoryDispatchContext,
-} from "../mockContext";
-
-describe("Mode Registry", () => {
-  const mockContext = createMockContext({
-    eventName: "issue_comment",
-    payload: {
-      action: "created",
-      comment: {
-        body: "Test comment without trigger",
-      },
-    } as any,
-  });
-
-  const mockWorkflowDispatchContext = createMockAutomationContext({
-    eventName: "workflow_dispatch",
-  });
-
-  const mockScheduleContext = createMockAutomationContext({
-    eventName: "schedule",
-  });
-
-  test("getMode auto-detects agent mode for issue_comment without trigger", () => {
-    const mode = getMode(mockContext);
-    // Agent mode is the default when no trigger is found
-    expect(mode).toBe(agentMode);
-    expect(mode.name).toBe("agent");
-  });
-
-  test("getMode auto-detects agent mode for workflow_dispatch", () => {
-    const mode = getMode(mockWorkflowDispatchContext);
-    expect(mode).toBe(agentMode);
-    expect(mode.name).toBe("agent");
-  });
-
-  // Removed test - explicit mode override no longer supported in v1.0
-
-  test("getMode auto-detects agent for workflow_dispatch", () => {
-    const mode = getMode(mockWorkflowDispatchContext);
-    expect(mode).toBe(agentMode);
-    expect(mode.name).toBe("agent");
-  });
-
-  test("getMode auto-detects agent for schedule event", () => {
-    const mode = getMode(mockScheduleContext);
-    expect(mode).toBe(agentMode);
-    expect(mode.name).toBe("agent");
-  });
-
-  test("getMode auto-detects agent for repository_dispatch event", () => {
-    const mode = getMode(mockRepositoryDispatchContext);
-    expect(mode).toBe(agentMode);
-    expect(mode.name).toBe("agent");
-  });
-
-  test("getMode auto-detects agent for repository_dispatch with client_payload", () => {
-    const contextWithPayload = createMockAutomationContext({
-      eventName: "repository_dispatch",
-      payload: {
-        action: "trigger-analysis",
-        client_payload: {
-          source: "external-system",
-          metadata: { priority: "high" },
-        },
-        repository: {
-          name: "test-repo",
-          owner: { login: "test-owner" },
-        },
-        sender: { login: "automation-user" },
-      },
-    });
-
-    const mode = getMode(contextWithPayload);
-    expect(mode).toBe(agentMode);
-    expect(mode.name).toBe("agent");
-  });
-
-  // Removed test - legacy mode names no longer supported in v1.0
-
-  test("getMode auto-detects agent mode for PR opened", () => {
-    const prContext = createMockContext({
-      eventName: "pull_request",
-      payload: { action: "opened" } as any,
-      isPR: true,
-    });
-    const mode = getMode(prContext);
-    expect(mode).toBe(agentMode);
-    expect(mode.name).toBe("agent");
-  });
-
-  test("getMode uses agent mode when prompt is provided, even with @claude mention", () => {
-    const contextWithPrompt = createMockContext({
-      eventName: "issue_comment",
-      payload: {
-        action: "created",
-        comment: {
-          body: "@claude please help",
-        },
-      } as any,
-      inputs: {
-        prompt: "/review",
-      } as any,
-    });
-    const mode = getMode(contextWithPrompt);
-    expect(mode).toBe(agentMode);
-    expect(mode.name).toBe("agent");
-  });
-
-  test("getMode uses tag mode for @claude mention without prompt", () => {
-    // Ensure PROMPT env var is not set (clean up from previous tests)
-    const originalPrompt = process.env.PROMPT;
-    delete process.env.PROMPT;
-
-    const contextWithMention = createMockContext({
-      eventName: "issue_comment",
-      payload: {
-        action: "created",
-        comment: {
-          body: "@claude please help",
-        },
-      } as any,
-      inputs: {
-        triggerPhrase: "@claude",
-        prompt: "",
-      } as any,
-    });
-    const mode = getMode(contextWithMention);
-    expect(mode).toBe(tagMode);
-    expect(mode.name).toBe("tag");
-
-    // Restore original value if it existed
-    if (originalPrompt !== undefined) {
-      process.env.PROMPT = originalPrompt;
-    }
-  });
-
-  // Removed test - explicit mode override no longer supported in v1.0
-
-  test("isValidMode returns true for all valid modes", () => {
-    expect(isValidMode("tag")).toBe(true);
-    expect(isValidMode("agent")).toBe(true);
-  });
-
-  test("isValidMode returns false for invalid mode", () => {
-    expect(isValidMode("invalid")).toBe(false);
-    expect(isValidMode("review")).toBe(false);
-  });
-});

test/modes/tag.test.ts

@@ -1,92 +1,8 @@
-import { describe, test, expect, beforeEach } from "bun:test";
-import { tagMode } from "../../src/modes/tag";
-import type { ParsedGitHubContext } from "../../src/github/context";
-import type { IssueCommentEvent } from "@octokit/webhooks-types";
-import { createMockContext } from "../mockContext";
+import { describe, test, expect } from "bun:test";
+import { prepareTagMode } from "../../src/modes/tag";
 
 describe("Tag Mode", () => {
-  let mockContext: ParsedGitHubContext;
-
-  beforeEach(() => {
-    mockContext = createMockContext({
-      eventName: "issue_comment",
-      isPR: false,
-    });
-  });
-
-  test("tag mode has correct properties", () => {
-    expect(tagMode.name).toBe("tag");
-    expect(tagMode.description).toBe(
-      "Traditional implementation mode triggered by @claude mentions",
-    );
-    expect(tagMode.shouldCreateTrackingComment()).toBe(true);
-  });
-
-  test("shouldTrigger delegates to checkContainsTrigger", () => {
-    const contextWithTrigger = createMockContext({
-      eventName: "issue_comment",
-      isPR: false,
-      inputs: {
-        ...createMockContext().inputs,
-        triggerPhrase: "@claude",
-      },
-      payload: {
-        comment: {
-          body: "Hey @claude, can you help?",
-        },
-      } as IssueCommentEvent,
-    });
-
-    expect(tagMode.shouldTrigger(contextWithTrigger)).toBe(true);
-
-    const contextWithoutTrigger = createMockContext({
-      eventName: "issue_comment",
-      isPR: false,
-      inputs: {
-        ...createMockContext().inputs,
-        triggerPhrase: "@claude",
-      },
-      payload: {
-        comment: {
-          body: "This is just a regular comment",
-        },
-      } as IssueCommentEvent,
-    });
-
-    expect(tagMode.shouldTrigger(contextWithoutTrigger)).toBe(false);
-  });
-
-  test("prepareContext includes all required data", () => {
-    const data = {
-      commentId: 123,
-      baseBranch: "main",
-      claudeBranch: "claude/fix-bug",
-    };
-
-    const context = tagMode.prepareContext(mockContext, data);
-
-    expect(context.mode).toBe("tag");
-    expect(context.githubContext).toBe(mockContext);
-    expect(context.commentId).toBe(123);
-    expect(context.baseBranch).toBe("main");
-    expect(context.claudeBranch).toBe("claude/fix-bug");
-  });
-
-  test("prepareContext works without data", () => {
-    const context = tagMode.prepareContext(mockContext);
-
-    expect(context.mode).toBe("tag");
-    expect(context.githubContext).toBe(mockContext);
-    expect(context.commentId).toBeUndefined();
-    expect(context.baseBranch).toBeUndefined();
-    expect(context.claudeBranch).toBeUndefined();
-  });
-
-  test("getAllowedTools returns empty array", () => {
-    expect(tagMode.getAllowedTools()).toEqual([]);
-  });
-
-  test("getDisallowedTools returns empty array", () => {
-    expect(tagMode.getDisallowedTools()).toEqual([]);
+  test("prepareTagMode is exported as a function", () => {
+    expect(typeof prepareTagMode).toBe("function");
   });
 });

test/pull-request-target.test.ts

@@ -1,38 +1,10 @@
 #!/usr/bin/env bun
 
 import { describe, test, expect } from "bun:test";
-import {
-  getEventTypeAndContext,
-  generatePrompt,
-  generateDefaultPrompt,
-} from "../src/create-prompt";
+import { getEventTypeAndContext, generatePrompt } from "../src/create-prompt";
 import type { PreparedContext } from "../src/create-prompt";
-import type { Mode } from "../src/modes/types";
 
 describe("pull_request_target event support", () => {
-  // Mock tag mode for testing
-  const mockTagMode: Mode = {
-    name: "tag",
-    description: "Tag mode",
-    shouldTrigger: () => true,
-    prepareContext: (context) => ({ mode: "tag", githubContext: context }),
-    getAllowedTools: () => [],
-    getDisallowedTools: () => [],
-    shouldCreateTrackingComment: () => true,
-    generatePrompt: (context, githubData, useCommitSigning) =>
-      generateDefaultPrompt(context, githubData, useCommitSigning),
-    prepare: async () => ({
-      commentId: 123,
-      branchInfo: {
-        baseBranch: "main",
-        currentBranch: "main",
-        claudeBranch: undefined,
-      },
-      mcpConfig: "{}",
-      claudeArgs: "",
-    }),
-  };
-
   const mockGitHubData = {
     contextData: {
       title: "External PR via pull_request_target",
@@ -126,12 +98,7 @@ describe("pull_request_target event support", () => {
         },
       };
 
-      const prompt = generatePrompt(
-        envVars,
-        mockGitHubData,
-        false,
-        mockTagMode,
-      );
+      const prompt = generatePrompt(envVars, mockGitHubData, false, "tag");
 
       // Should contain pull request event type and metadata
       expect(prompt).toContain("<event_type>PULL_REQUEST</event_type>");
@@ -165,12 +132,7 @@ describe("pull_request_target event support", () => {
         },
       };
 
-      const prompt = generatePrompt(
-        envVars,
-        mockGitHubData,
-        false,
-        mockTagMode,
-      );
+      const prompt = generatePrompt(envVars, mockGitHubData, false, "tag");
 
       // Should include git commands for non-commit-signing mode
       expect(prompt).toContain("git push");
@@ -196,7 +158,7 @@ describe("pull_request_target event support", () => {
         },
       };
 
-      const prompt = generatePrompt(envVars, mockGitHubData, true, mockTagMode);
+      const prompt = generatePrompt(envVars, mockGitHubData, true, "tag");
 
       // Should include commit signing tools
       expect(prompt).toContain("mcp__github_file_ops__commit_files");
@@ -246,13 +208,13 @@ describe("pull_request_target event support", () => {
         pullRequestContext,
         mockGitHubData,
         false,
-        mockTagMode,
+        "tag",
       );
       const pullRequestTargetPrompt = generatePrompt(
         pullRequestTargetContext,
         mockGitHubData,
         false,
-        mockTagMode,
+        "tag",
       );
 
       // Both should have the same event type and structure
@@ -293,37 +255,7 @@ describe("pull_request_target event support", () => {
         },
       };
 
-      // Use agent mode which passes through the prompt as-is
-      const mockAgentMode: Mode = {
-        name: "agent",
-        description: "Agent mode",
-        shouldTrigger: () => true,
-        prepareContext: (context) => ({
-          mode: "agent",
-          githubContext: context,
-        }),
-        getAllowedTools: () => [],
-        getDisallowedTools: () => [],
-        shouldCreateTrackingComment: () => true,
-        generatePrompt: (context) => context.prompt || "default prompt",
-        prepare: async () => ({
-          commentId: 123,
-          branchInfo: {
-            baseBranch: "main",
-            currentBranch: "main",
-            claudeBranch: undefined,
-          },
-          mcpConfig: "{}",
-          claudeArgs: "",
-        }),
-      };
-
-      const prompt = generatePrompt(
-        envVars,
-        mockGitHubData,
-        false,
-        mockAgentMode,
-      );
+      const prompt = generatePrompt(envVars, mockGitHubData, false, "agent");
 
       expect(prompt).toBe(
         "Review this pull_request_target PR for security issues",
@@ -343,12 +275,7 @@ describe("pull_request_target event support", () => {
         },
       };
 
-      const prompt = generatePrompt(
-        envVars,
-        mockGitHubData,
-        false,
-        mockTagMode,
-      );
+      const prompt = generatePrompt(envVars, mockGitHubData, false, "tag");
 
       // Should generate default prompt structure
       expect(prompt).toContain("<event_type>PULL_REQUEST</event_type>");
@@ -418,7 +345,7 @@ describe("pull_request_target event support", () => {
 
       // Should not throw when generating prompt
       expect(() => {
-        generatePrompt(minimalContext, mockGitHubData, false, mockTagMode);
+        generatePrompt(minimalContext, mockGitHubData, false, "tag");
       }).not.toThrow();
     });
 
@@ -476,13 +403,13 @@ describe("pull_request_target event support", () => {
         internalPR,
         mockGitHubData,
         false,
-        mockTagMode,
+        "tag",
       );
       const externalPrompt = generatePrompt(
         externalPR,
         mockGitHubData,
         false,
-        mockTagMode,
+        "tag",
       );
 
       // Should have same tool access patterns