stack/apps/api/src/continuation-prompts/continuation-prompts.service.spec.ts

import { describe, it, expect, beforeEach } from "vitest";
import { ContinuationPromptsService } from "./continuation-prompts.service";
import { ContinuationPromptContext, FailureDetail, ContinuationPrompt } from "./interfaces";

describe("ContinuationPromptsService", () => {
  let service: ContinuationPromptsService;
  let baseContext: ContinuationPromptContext;

  beforeEach(() => {
    service = new ContinuationPromptsService();
    baseContext = {
      taskId: "task-1",
      originalTask: "Implement user authentication",
      attemptNumber: 1,
      maxAttempts: 3,
      failures: [],
      filesChanged: ["src/auth/auth.service.ts"],
    };
  });

  describe("generatePrompt", () => {
    it("should generate a prompt with system and user sections", () => {
      const context: ContinuationPromptContext = {
        ...baseContext,
        failures: [
          {
            type: "test-failure",
            message: "Test failed: should authenticate user",
            details: "Expected 200, got 401",
          },
        ],
      };

      const prompt = service.generatePrompt(context);

      expect(prompt).toBeDefined();
      expect(prompt.systemPrompt).toContain("CRITICAL RULES");
      expect(prompt.userPrompt).toContain("Implement user authentication");
      expect(prompt.userPrompt).toContain("Test failed");
      expect(prompt.constraints).toBeInstanceOf(Array);
      expect(prompt.priority).toBe("high");
    });

    it("should include attempt number in prompt", () => {
      const context: ContinuationPromptContext = {
        ...baseContext,
        attemptNumber: 2,
        failures: [
          {
            type: "build-error",
            message: "Type error in auth.service.ts",
          },
        ],
      };

      const prompt = service.generatePrompt(context);

      expect(prompt.userPrompt).toContain("attempt 2 of 3");
    });

    it("should escalate priority on final attempt", () => {
      const context: ContinuationPromptContext = {
        ...baseContext,
        attemptNumber: 3,
        maxAttempts: 3,
        failures: [
          {
            type: "test-failure",
            message: "Tests still failing",
          },
        ],
      };

      const prompt = service.generatePrompt(context);

      expect(prompt.priority).toBe("critical");
      expect(prompt.constraints).toContain(
        "This is your LAST attempt. Failure means manual intervention required."
      );
    });

    it("should handle multiple failure types", () => {
      const context: ContinuationPromptContext = {
        ...baseContext,
        failures: [
          {
            type: "test-failure",
            message: "Auth test failed",
          },
          {
            type: "build-error",
            message: "Type error",
          },
          {
            type: "coverage",
            message: "Coverage below 85%",
          },
        ],
      };

      const prompt = service.generatePrompt(context);

      expect(prompt.userPrompt).toContain("Auth test failed");
      expect(prompt.userPrompt).toContain("Type error");
      expect(prompt.userPrompt).toContain("Coverage below 85%");
    });
  });

  describe("generateTestFailurePrompt", () => {
    it("should format test failures with details", () => {
      const failures: FailureDetail[] = [
        {
          type: "test-failure",
          message: "should authenticate user",
          details: "Expected 200, got 401",
          location: "auth.service.spec.ts:42",
        },
        {
          type: "test-failure",
          message: "should reject invalid credentials",
          details: "AssertionError: expected false to be true",
          location: "auth.service.spec.ts:58",
        },
      ];

      const prompt = service.generateTestFailurePrompt(failures);

      expect(prompt).toContain("should authenticate user");
      expect(prompt).toContain("Expected 200, got 401");
      expect(prompt).toContain("auth.service.spec.ts:42");
      expect(prompt).toContain("should reject invalid credentials");
      expect(prompt).toContain("Fix the implementation");
    });

    it("should include guidance for fixing tests", () => {
      const failures: FailureDetail[] = [
        {
          type: "test-failure",
          message: "Test failed",
        },
      ];

      const prompt = service.generateTestFailurePrompt(failures);

      expect(prompt).toContain("Read the test");
      expect(prompt).toContain("Fix the implementation");
      expect(prompt).toContain("Run the test");
    });
  });

  describe("generateBuildErrorPrompt", () => {
    it("should format build errors with location", () => {
      const failures: FailureDetail[] = [
        {
          type: "build-error",
          message: "Type 'string' is not assignable to type 'number'",
          location: "auth.service.ts:25",
        },
        {
          type: "build-error",
          message: "Cannot find name 'User'",
          location: "auth.service.ts:42",
          suggestion: "Import User from '@/entities'",
        },
      ];

      const prompt = service.generateBuildErrorPrompt(failures);

      expect(prompt).toContain("Type 'string' is not assignable");
      expect(prompt).toContain("auth.service.ts:25");
      expect(prompt).toContain("Cannot find name 'User'");
      expect(prompt).toContain("Import User from");
    });

    it("should include build-specific guidance", () => {
      const failures: FailureDetail[] = [
        {
          type: "build-error",
          message: "Syntax error",
        },
      ];

      const prompt = service.generateBuildErrorPrompt(failures);

      expect(prompt).toContain("TypeScript");
      expect(prompt).toContain("Do not proceed until build passes");
    });
  });

  describe("generateCoveragePrompt", () => {
    it("should show coverage gap", () => {
      const prompt = service.generateCoveragePrompt(72, 85);

      expect(prompt).toContain("72%");
      expect(prompt).toContain("85%");
      expect(prompt).toContain("13%"); // gap
    });

    it("should provide guidance for improving coverage", () => {
      const prompt = service.generateCoveragePrompt(80, 85);

      expect(prompt).toContain("uncovered code paths");
      expect(prompt).toContain("edge cases");
      expect(prompt).toContain("error handling");
    });
  });

  describe("generateIncompleteWorkPrompt", () => {
    it("should list incomplete work items", () => {
      const issues = [
        "TODO: Implement password hashing",
        "FIXME: Add error handling",
        "Missing validation for email format",
      ];

      const prompt = service.generateIncompleteWorkPrompt(issues);

      expect(prompt).toContain("TODO: Implement password hashing");
      expect(prompt).toContain("FIXME: Add error handling");
      expect(prompt).toContain("Missing validation");
    });

    it("should emphasize completion requirement", () => {
      const issues = ["Missing feature X"];

      const prompt = service.generateIncompleteWorkPrompt(issues);

      expect(prompt).toContain("MUST complete ALL aspects");
      expect(prompt).toContain("Do not leave TODO");
    });
  });

  describe("getConstraints", () => {
    it("should return basic constraints for first attempt", () => {
      const constraints = service.getConstraints(1, 3);

      expect(constraints).toBeInstanceOf(Array);
      expect(constraints.length).toBeGreaterThan(0);
    });

    it("should escalate constraints on second attempt", () => {
      const constraints = service.getConstraints(2, 3);

      expect(constraints).toContain("Focus only on failures, no new features");
    });

    it("should add strict constraints on third attempt", () => {
      const constraints = service.getConstraints(3, 3);

      expect(constraints).toContain("Minimal changes only, fix exact issues");
    });

    it("should add final warning on last attempt", () => {
      const constraints = service.getConstraints(3, 3);

      expect(constraints).toContain(
        "This is your LAST attempt. Failure means manual intervention required."
      );
    });

    it("should handle different max attempts", () => {
      const constraints = service.getConstraints(5, 5);

      expect(constraints).toContain(
        "This is your LAST attempt. Failure means manual intervention required."
      );
    });
  });

  describe("formatFailuresForPrompt", () => {
    it("should format failures with all details", () => {
      const failures: FailureDetail[] = [
        {
          type: "test-failure",
          message: "Test failed",
          details: "Expected true, got false",
          location: "file.spec.ts:10",
          suggestion: "Check the implementation",
        },
      ];

      const formatted = service.formatFailuresForPrompt(failures);

      expect(formatted).toContain("test-failure");
      expect(formatted).toContain("Test failed");
      expect(formatted).toContain("Expected true, got false");
      expect(formatted).toContain("file.spec.ts:10");
      expect(formatted).toContain("Check the implementation");
    });

    it("should handle failures without optional fields", () => {
      const failures: FailureDetail[] = [
        {
          type: "lint-error",
          message: "Unused variable",
        },
      ];

      const formatted = service.formatFailuresForPrompt(failures);

      expect(formatted).toContain("lint-error");
      expect(formatted).toContain("Unused variable");
    });

    it("should format multiple failures", () => {
      const failures: FailureDetail[] = [
        {
          type: "test-failure",
          message: "Test 1 failed",
        },
        {
          type: "build-error",
          message: "Build error",
        },
        {
          type: "coverage",
          message: "Low coverage",
        },
      ];

      const formatted = service.formatFailuresForPrompt(failures);

      expect(formatted).toContain("Test 1 failed");
      expect(formatted).toContain("Build error");
      expect(formatted).toContain("Low coverage");
    });

    it("should handle empty failures array", () => {
      const failures: FailureDetail[] = [];

      const formatted = service.formatFailuresForPrompt(failures);

      expect(formatted).toBe("");
    });
  });

  describe("priority assignment", () => {
    it("should set normal priority for first attempt with minor issues", () => {
      const context: ContinuationPromptContext = {
        ...baseContext,
        attemptNumber: 1,
        failures: [
          {
            type: "lint-error",
            message: "Minor lint issue",
          },
        ],
      };

      const prompt = service.generatePrompt(context);

      expect(prompt.priority).toBe("normal");
    });

    it("should set high priority for build errors", () => {
      const context: ContinuationPromptContext = {
        ...baseContext,
        failures: [
          {
            type: "build-error",
            message: "Build failed",
          },
        ],
      };

      const prompt = service.generatePrompt(context);

      expect(prompt.priority).toBe("high");
    });

    it("should set high priority for test failures", () => {
      const context: ContinuationPromptContext = {
        ...baseContext,
        failures: [
          {
            type: "test-failure",
            message: "Test failed",
          },
        ],
      };

      const prompt = service.generatePrompt(context);

      expect(prompt.priority).toBe("high");
    });
  });
});