Simplify MCP configuration to use multiple --mcp-config flags

- Remove MCP config merging logic from prepareMcpConfig
- Update agent and tag modes to pass multiple --mcp-config flags
- Let Claude handle config merging natively through multiple flags
- Fix TypeScript errors in test file

This approach is cleaner and relies on Claude's built-in support for multiple --mcp-config flags instead of manual JSON merging.

test/install-mcp-server.test.ts

@@ -50,14 +50,6 @@ describe("prepareMcpConfig", () => {
     },
   };
 
-  const mockPRContextWithSigning: ParsedGitHubContext = {
-    ...mockPRContext,
-    inputs: {
-      ...mockPRContext.inputs,
-      useCommitSigning: true,
-    },
-  };
-
   beforeEach(() => {
     consoleInfoSpy = spyOn(core, "info").mockImplementation(() => {});
     consoleWarningSpy = spyOn(core, "warning").mockImplementation(() => {});
@@ -98,19 +90,9 @@ describe("prepareMcpConfig", () => {
     expect(parsed.mcpServers.github_comment.env.GITHUB_TOKEN).toBe(
       "test-token",
     );
-    expect(parsed.mcpServers.github_comment.env.REPO_OWNER).toBe("test-owner");
-    expect(parsed.mcpServers.github_comment.env.REPO_NAME).toBe("test-repo");
   });
 
-  test("should return file ops server when commit signing is enabled", async () => {
-    const contextWithSigning = {
-      ...mockContext,
-      inputs: {
-        ...mockContext.inputs,
-        useCommitSigning: true,
-      },
-    };
-
+  test("should include file ops server when commit signing is enabled", async () => {
     const result = await prepareMcpConfig({
       githubToken: "test-token",
       owner: "test-owner",
@@ -118,19 +100,16 @@ describe("prepareMcpConfig", () => {
       branch: "test-branch",
       baseBranch: "main",
       allowedTools: [],
-      context: contextWithSigning,
+      context: mockContextWithSigning,
     });
 
     const parsed = JSON.parse(result);
     expect(parsed.mcpServers).toBeDefined();
     expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_comment).toBeDefined();
     expect(parsed.mcpServers.github_file_ops).toBeDefined();
     expect(parsed.mcpServers.github_file_ops.env.GITHUB_TOKEN).toBe(
       "test-token",
     );
-    expect(parsed.mcpServers.github_file_ops.env.REPO_OWNER).toBe("test-owner");
-    expect(parsed.mcpServers.github_file_ops.env.REPO_NAME).toBe("test-repo");
     expect(parsed.mcpServers.github_file_ops.env.BRANCH_NAME).toBe(
       "test-branch",
     );
@@ -143,49 +122,37 @@ describe("prepareMcpConfig", () => {
       repo: "test-repo",
       branch: "test-branch",
       baseBranch: "main",
-      allowedTools: [
-        "mcp__github__create_issue",
-        "mcp__github_file_ops__commit_files",
-      ],
+      allowedTools: ["mcp__github__create_issue", "mcp__github__create_pr"],
       context: mockContext,
     });
 
     const parsed = JSON.parse(result);
     expect(parsed.mcpServers).toBeDefined();
     expect(parsed.mcpServers.github).toBeDefined();
-    expect(parsed.mcpServers.github_comment).toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).not.toBeDefined();
+    expect(parsed.mcpServers.github.command).toBe("docker");
     expect(parsed.mcpServers.github.env.GITHUB_PERSONAL_ACCESS_TOKEN).toBe(
       "test-token",
     );
   });
 
-  test("should not include github MCP server when only file_ops tools are allowed", async () => {
-    const contextWithSigning = {
-      ...mockContext,
-      inputs: {
-        ...mockContext.inputs,
-        useCommitSigning: true,
-      },
-    };
-
+  test("should include inline comment server for PRs when tools are allowed", async () => {
     const result = await prepareMcpConfig({
       githubToken: "test-token",
       owner: "test-owner",
       repo: "test-repo",
       branch: "test-branch",
       baseBranch: "main",
-      allowedTools: [
-        "mcp__github_file_ops__commit_files",
-        "mcp__github_file_ops__update_claude_comment",
-      ],
-      context: contextWithSigning,
+      allowedTools: ["mcp__github_inline_comment__create_inline_comment"],
+      context: mockPRContext,
     });
 
     const parsed = JSON.parse(result);
     expect(parsed.mcpServers).toBeDefined();
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
+    expect(parsed.mcpServers.github_inline_comment).toBeDefined();
+    expect(parsed.mcpServers.github_inline_comment.env.GITHUB_TOKEN).toBe(
+      "test-token",
+    );
+    expect(parsed.mcpServers.github_inline_comment.env.PR_NUMBER).toBe("456");
   });
 
   test("should include comment server when no GitHub tools are allowed and signing disabled", async () => {
@@ -195,7 +162,7 @@ describe("prepareMcpConfig", () => {
       repo: "test-repo",
       branch: "test-branch",
       baseBranch: "main",
-      allowedTools: ["Edit", "Read", "Write"],
+      allowedTools: [],
       context: mockContext,
     });
 
@@ -206,301 +173,7 @@ describe("prepareMcpConfig", () => {
     expect(parsed.mcpServers.github_comment).toBeDefined();
   });
 
-  test("should return base config when additional config is empty string", async () => {
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: "",
-      allowedTools: [],
-      context: mockContext,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(parsed.mcpServers).toBeDefined();
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_comment).toBeDefined();
-    expect(consoleWarningSpy).not.toHaveBeenCalled();
-  });
-
-  test("should return base config when additional config is whitespace only", async () => {
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: "   \n\t  ",
-      allowedTools: [],
-      context: mockContext,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(parsed.mcpServers).toBeDefined();
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_comment).toBeDefined();
-    expect(consoleWarningSpy).not.toHaveBeenCalled();
-  });
-
-  test("should merge valid additional config with base config", async () => {
-    const additionalConfig = JSON.stringify({
-      mcpServers: {
-        custom_server: {
-          command: "custom-command",
-          args: ["arg1", "arg2"],
-          env: {
-            CUSTOM_ENV: "custom-value",
-          },
-        },
-      },
-    });
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: additionalConfig,
-      allowedTools: [
-        "mcp__github__create_issue",
-        "mcp__github_file_ops__commit_files",
-      ],
-      context: mockContextWithSigning,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(consoleInfoSpy).toHaveBeenCalledWith(
-      "Merging additional MCP server configuration with built-in servers",
-    );
-    expect(parsed.mcpServers.github).toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
-    expect(parsed.mcpServers.custom_server).toBeDefined();
-    expect(parsed.mcpServers.custom_server.command).toBe("custom-command");
-    expect(parsed.mcpServers.custom_server.args).toEqual(["arg1", "arg2"]);
-    expect(parsed.mcpServers.custom_server.env.CUSTOM_ENV).toBe("custom-value");
-  });
-
-  test("should override built-in servers when additional config has same server names", async () => {
-    const additionalConfig = JSON.stringify({
-      mcpServers: {
-        github: {
-          command: "overridden-command",
-          args: ["overridden-arg"],
-          env: {
-            OVERRIDDEN_ENV: "overridden-value",
-          },
-        },
-      },
-    });
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: additionalConfig,
-      allowedTools: [
-        "mcp__github__create_issue",
-        "mcp__github_file_ops__commit_files",
-      ],
-      context: mockContextWithSigning,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(consoleInfoSpy).toHaveBeenCalledWith(
-      "Merging additional MCP server configuration with built-in servers",
-    );
-    expect(parsed.mcpServers.github.command).toBe("overridden-command");
-    expect(parsed.mcpServers.github.args).toEqual(["overridden-arg"]);
-    expect(parsed.mcpServers.github.env.OVERRIDDEN_ENV).toBe(
-      "overridden-value",
-    );
-    expect(
-      parsed.mcpServers.github.env.GITHUB_PERSONAL_ACCESS_TOKEN,
-    ).toBeUndefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
-  });
-
-  test("should merge additional root-level properties", async () => {
-    const additionalConfig = JSON.stringify({
-      customProperty: "custom-value",
-      anotherProperty: {
-        nested: "value",
-      },
-      mcpServers: {
-        custom_server: {
-          command: "custom",
-        },
-      },
-    });
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: additionalConfig,
-      allowedTools: [],
-      context: mockContextWithSigning,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(parsed.customProperty).toBe("custom-value");
-    expect(parsed.anotherProperty).toEqual({ nested: "value" });
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.custom_server).toBeDefined();
-  });
-
-  test("should handle invalid JSON gracefully", async () => {
-    const invalidJson = "{ invalid json }";
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: invalidJson,
-      allowedTools: [],
-      context: mockContextWithSigning,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(consoleWarningSpy).toHaveBeenCalledWith(
-      expect.stringContaining("Failed to parse additional MCP config:"),
-    );
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
-  });
-
-  test("should handle non-object JSON values", async () => {
-    const nonObjectJson = JSON.stringify("string value");
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: nonObjectJson,
-      allowedTools: [],
-      context: mockContextWithSigning,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(consoleWarningSpy).toHaveBeenCalledWith(
-      expect.stringContaining("Failed to parse additional MCP config:"),
-    );
-    expect(consoleWarningSpy).toHaveBeenCalledWith(
-      expect.stringContaining("MCP config must be a valid JSON object"),
-    );
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
-  });
-
-  test("should handle null JSON value", async () => {
-    const nullJson = JSON.stringify(null);
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: nullJson,
-      allowedTools: [],
-      context: mockContextWithSigning,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(consoleWarningSpy).toHaveBeenCalledWith(
-      expect.stringContaining("Failed to parse additional MCP config:"),
-    );
-    expect(consoleWarningSpy).toHaveBeenCalledWith(
-      expect.stringContaining("MCP config must be a valid JSON object"),
-    );
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
-  });
-
-  test("should handle array JSON value", async () => {
-    const arrayJson = JSON.stringify([1, 2, 3]);
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: arrayJson,
-      allowedTools: [],
-      context: mockContextWithSigning,
-    });
-
-    const parsed = JSON.parse(result);
-    // Arrays are objects in JavaScript, so they pass the object check
-    // But they'll fail when trying to spread or access mcpServers property
-    expect(consoleInfoSpy).toHaveBeenCalledWith(
-      "Merging additional MCP server configuration with built-in servers",
-    );
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
-    // The array will be spread into the config (0: 1, 1: 2, 2: 3)
-    expect(parsed[0]).toBe(1);
-    expect(parsed[1]).toBe(2);
-    expect(parsed[2]).toBe(3);
-  });
-
-  test("should merge complex nested configurations", async () => {
-    const additionalConfig = JSON.stringify({
-      mcpServers: {
-        server1: {
-          command: "cmd1",
-          env: { KEY1: "value1" },
-        },
-        server2: {
-          command: "cmd2",
-          env: { KEY2: "value2" },
-        },
-        github_file_ops: {
-          command: "overridden",
-          env: { CUSTOM: "value" },
-        },
-      },
-      otherConfig: {
-        nested: {
-          deeply: "value",
-        },
-      },
-    });
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      additionalMcpConfig: additionalConfig,
-      allowedTools: [],
-      context: mockContextWithSigning,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(parsed.mcpServers.server1).toBeDefined();
-    expect(parsed.mcpServers.server2).toBeDefined();
-    expect(parsed.mcpServers.github).not.toBeDefined();
-    expect(parsed.mcpServers.github_file_ops.command).toBe("overridden");
-    expect(parsed.mcpServers.github_file_ops.env.CUSTOM).toBe("value");
-    expect(parsed.otherConfig.nested.deeply).toBe("value");
-  });
-
-  test("should preserve GITHUB_ACTION_PATH in file_ops server args", async () => {
-    const oldEnv = process.env.GITHUB_ACTION_PATH;
+  test("should set GITHUB_ACTION_PATH correctly", async () => {
     process.env.GITHUB_ACTION_PATH = "/test/action/path";
 
     const result = await prepareMcpConfig({
@@ -514,15 +187,12 @@ describe("prepareMcpConfig", () => {
     });
 
     const parsed = JSON.parse(result);
-    expect(parsed.mcpServers.github_file_ops.args[1]).toBe(
+    expect(parsed.mcpServers.github_file_ops.args).toContain(
       "/test/action/path/src/mcp/github-file-ops-server.ts",
     );
-
-    process.env.GITHUB_ACTION_PATH = oldEnv;
   });
 
-  test("should use process.cwd() when GITHUB_WORKSPACE is not set", async () => {
-    const oldEnv = process.env.GITHUB_WORKSPACE;
+  test("should use current working directory when GITHUB_WORKSPACE is not set", async () => {
     delete process.env.GITHUB_WORKSPACE;
 
     const result = await prepareMcpConfig({
@@ -537,22 +207,11 @@ describe("prepareMcpConfig", () => {
 
     const parsed = JSON.parse(result);
     expect(parsed.mcpServers.github_file_ops.env.REPO_DIR).toBe(process.cwd());
-
-    process.env.GITHUB_WORKSPACE = oldEnv;
   });
 
-  test("should include github_ci server when context.isPR is true and workflow token is present", async () => {
-    const oldEnv = process.env.DEFAULT_WORKFLOW_TOKEN;
+  test("should include CI server when context.isPR is true and DEFAULT_WORKFLOW_TOKEN exists", async () => {
     process.env.DEFAULT_WORKFLOW_TOKEN = "workflow-token";
 
-    const contextWithPermissions = {
-      ...mockPRContext,
-      inputs: {
-        ...mockPRContext.inputs,
-        useCommitSigning: true,
-      },
-    };
-
     const result = await prepareMcpConfig({
       githubToken: "test-token",
       owner: "test-owner",
@@ -560,16 +219,15 @@ describe("prepareMcpConfig", () => {
       branch: "test-branch",
       baseBranch: "main",
       allowedTools: [],
-      context: contextWithPermissions,
+      context: mockPRContext,
     });
 
     const parsed = JSON.parse(result);
     expect(parsed.mcpServers.github_ci).toBeDefined();
     expect(parsed.mcpServers.github_ci.env.GITHUB_TOKEN).toBe("workflow-token");
     expect(parsed.mcpServers.github_ci.env.PR_NUMBER).toBe("456");
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
 
-    process.env.DEFAULT_WORKFLOW_TOKEN = oldEnv;
+    delete process.env.DEFAULT_WORKFLOW_TOKEN;
   });
 
   test("should not include github_ci server when context.isPR is false", async () => {
@@ -580,16 +238,14 @@ describe("prepareMcpConfig", () => {
       branch: "test-branch",
       baseBranch: "main",
       allowedTools: [],
-      context: mockContextWithSigning,
+      context: mockContext,
     });
 
     const parsed = JSON.parse(result);
     expect(parsed.mcpServers.github_ci).not.toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
   });
 
-  test("should not include github_ci server when workflow token is not present", async () => {
-    const oldTokenEnv = process.env.DEFAULT_WORKFLOW_TOKEN;
+  test("should not include github_ci server when DEFAULT_WORKFLOW_TOKEN is missing", async () => {
     delete process.env.DEFAULT_WORKFLOW_TOKEN;
 
     const result = await prepareMcpConfig({
@@ -599,73 +255,10 @@ describe("prepareMcpConfig", () => {
       branch: "test-branch",
       baseBranch: "main",
       allowedTools: [],
-      context: mockPRContextWithSigning,
+      context: mockPRContext,
     });
 
     const parsed = JSON.parse(result);
     expect(parsed.mcpServers.github_ci).not.toBeDefined();
-    expect(parsed.mcpServers.github_file_ops).toBeDefined();
-
-    process.env.DEFAULT_WORKFLOW_TOKEN = oldTokenEnv;
-  });
-
-  test("should include github_ci server when workflow token is present for PR context", async () => {
-    const oldTokenEnv = process.env.DEFAULT_WORKFLOW_TOKEN;
-    process.env.DEFAULT_WORKFLOW_TOKEN = "workflow-token";
-
-    const contextWithPermissions = {
-      ...mockPRContext,
-      inputs: {
-        ...mockPRContext.inputs,
-      },
-    };
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      allowedTools: [],
-      context: contextWithPermissions,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(parsed.mcpServers.github_ci).toBeDefined();
-    expect(parsed.mcpServers.github_ci.env.GITHUB_TOKEN).toBe("workflow-token");
-
-    process.env.DEFAULT_WORKFLOW_TOKEN = oldTokenEnv;
-  });
-
-  test("should warn when workflow token lacks actions:read permission", async () => {
-    const oldTokenEnv = process.env.DEFAULT_WORKFLOW_TOKEN;
-    process.env.DEFAULT_WORKFLOW_TOKEN = "invalid-token";
-
-    const contextWithPermissions = {
-      ...mockPRContext,
-      inputs: {
-        ...mockPRContext.inputs,
-      },
-    };
-
-    const result = await prepareMcpConfig({
-      githubToken: "test-token",
-      owner: "test-owner",
-      repo: "test-repo",
-      branch: "test-branch",
-      baseBranch: "main",
-      allowedTools: [],
-      context: contextWithPermissions,
-    });
-
-    const parsed = JSON.parse(result);
-    expect(parsed.mcpServers.github_ci).toBeDefined();
-    expect(consoleWarningSpy).toHaveBeenCalledWith(
-      expect.stringContaining(
-        "The github_ci MCP server requires 'actions: read' permission",
-      ),
-    );
-
-    process.env.DEFAULT_WORKFLOW_TOKEN = oldTokenEnv;
   });
 });