Writing Implementation Test Pseudocode

Writing Implementation Test Pseudocode

Overview

Test implementation pseudocode uses Vitest syntax with placeholder comments that show WHAT to test and WHY it matters, without providing complete HOW implementations.

This follows MEDIUM-IMPLEMENTATION abstraction level: shows test structure and architectural decisions while using placeholder comments for complex logic. Teaches developers what to research and decide, not line-by-line implementation.

Core principle: Guide architectural thinking for tests, not implementation details.

When to Use

Use when:

• Adding test examples to user stories (Dev Notes sections)
• Documenting test patterns in technical specifications
• Showing test structure for developers who will implement
• Token efficiency matters (~60% reduction vs full implementation)

Don't use for:

• Complete working test code (use actual tests)
• Test documentation for end users (use prose)
• Abstract test theory (use traditional documentation)

Required Elements

Every test pseudocode MUST include:

1. Vitest terminology (describe, it, expect, beforeEach) - teaches framework correctly
2. Placeholder comments for complex logic (/* filter logic */ not .filter(x => x.valid))
3. Strategic comments (Research/Fixture/Integration/Verification/Pattern/Decision)
4. Test phase markers (Given-When-Then or Arrange-Act-Assert)
5. What's real vs abstract - mark integration boundaries explicitly

Without these elements, test pseudocode is incomplete.

Core Pattern

Before (Complete Implementation - Too Detailed)

it("should derive summary counts from enriched links", async () => {
  const { summary, links } = await validator.validateFile(mixedValidationSourcePath);

  const manualCounts = {
    total: links.length,
    valid: links.filter(link => link.validation.status === "valid").length,
    errors: links.filter(link => link.validation.status === "error").length,
    warnings: links.filter(link => link.validation.status === "warning").length
  };

  expect(summary.total).toBe(manualCounts.total);
  expect(summary.valid).toBe(manualCounts.valid);
});

After (MEDIUM-IMPLEMENTATION - Architectural Guidance)

it("should derive summary counts from enriched links", async () => {
  // Given: File with 3 valid, 2 error, 1 warning links
  // When: Validation completes
  const { summary, links } = /* await validator.validateFile(...) */;

  // Then: Summary matches link.validation.status counts
  // Verification: Summary derives from links, not separate calculation
  const manualCounts = {
    total: links.length,
    valid: /* count links where validation.status === "valid" */,
    errors: /* count links where validation.status === "error" */,
    warnings: /* count links where validation.status === "warning" */
  };

  // Pattern: Compare aggregate calculation to stored summary
  expect(summary.total).toBe(manualCounts.total);
  expect(summary.valid).toBe(manualCounts.valid);
});

Quick Reference

Strategic Comment Types

Research

Marks what developer needs to investigate - external patterns, libraries, or approaches.

// Research: Vitest fixture patterns for workspace isolation
// Research: DI setup for test components without mocks
beforeEach(() => {
  /* setup test environment */
});

Fixture

Explains test data and environment setup decisions - what's realistic vs minimal.

// Fixture: Real markdown file with mixed valid/invalid citations
const testFile = /* resolve fixture path */;

// Fixture: Use actual file system, not in-memory mock (integration test)
const validator = /* create with real dependencies */;

Integration

Shows what's real vs mocked - critical for understanding test boundaries.

// Integration: Real MarkdownParser with file system access
// Integration: Null for unused LinkResolver dependency (not under test)
validator = /* new CitationValidator(cache, null) */;

Verification

Explains what's being tested and why - the assertion strategy.

// Verification: LinkObject enriched with validation property (not separate results)
expect(link).toHaveProperty("validation");

// Verification: Valid links have status="valid" with no error fields
expect(validLink.validation.status).toBe("valid");
expect(validLink.validation).not.toHaveProperty("error");

Pattern

Identifies test structure or algorithm approach being demonstrated.

// Pattern: Given-When-Then structure for behavioral testing
// Given: Real markdown file
// When: Validate file
// Then: Verify enriched structure

// Pattern: Compare aggregate calculation to stored summary
const manualCounts = /* derive from links array */;
expect(summary.total).toBe(manualCounts.total);

Decision

Explains why test makes particular choices, especially edge cases.

// Decision: Verify summary derives FROM links, not vice versa (directionality)
const manualCounts = /* count from links.validation.status */;

// Decision: Test illegal state prevention (valid should never have error)
expect(validLink.validation).not.toHaveProperty("error");

Placeholder Comment Patterns

Use placeholder comments to abstract implementation details:

// ❌ Too detailed - shows complete implementation
const valid = links.filter(link => link.validation.status === "valid").length;

// ✅ Abstracted - shows intent, developer implements
const valid = /* count links where validation.status === "valid" */;

// ❌ Too detailed - complete object construction
const validator = new CitationValidator(new ParsedFileCache(new MarkdownParser(fs)), null);

// ✅ Abstracted - shows what's real vs null
validator = /* new CitationValidator(cache, null) */;

// ❌ Too detailed - actual import syntax
import { describe, it, expect, beforeEach } from "vitest";

// ✅ Abstracted - shows framework, not import mechanics
import { /* Vitest test functions */ } from "vitest";

Test Phase Markers

Always mark test phases explicitly:

it("should enrich valid links with validation status", async () => {
  // Given: File with valid citations
  const result = /* await validator.validateFile(testFile) */;

  // When: Validation completes
  const { links } = result;

  // Then: Valid links enriched with status="valid"
  // Verification: Status exists and correct, no error properties
  const validLink = /* find first valid link */;
  expect(validLink.validation.status).toBe("valid");
  expect(validLink.validation).not.toHaveProperty("error");
});

Real vs Abstract Guidelines

SHOW (concrete)

• Vitest structure (describe, it, beforeEach blocks)
• Test phases (Given-When-Then comments)
• Property access patterns (link.validation.status)
• Strategic architectural decisions
• What's being verified (expect statements with clear purpose)

ABSTRACT (placeholder comments)

• Complex filtering/mapping logic
• Object construction with dependencies
• Import details
• Loop bodies
• Count/aggregate calculations
• Array manipulation

// ✅ SHOW: Test structure and phases
describe("CitationValidator Enrichment", () => {
  beforeEach(() => {
    // Integration: Real components with DI (no mocks)
    validator = /* new CitationValidator(cache, null) */;
  });

  it("should derive summary from links", async () => {
    // Given: File with mixed validation states
    // When: Validation completes
    const { summary, links } = /* await validator.validateFile(...) */;

    // Then: Summary matches link counts
    // ABSTRACT: Count logic
    const manualCounts = {
      total: links.length,  // SHOW: Simple property access
      valid: /* count links where validation.status === "valid" */  // ABSTRACT: Filter logic
    };

    expect(summary.valid).toBe(manualCounts.valid);
  });
});

Token Efficiency

Test pseudocode in user stories should target ~200-300 words vs ~800+ words for complete implementation.

Techniques:

• Use placeholder comments for all complex logic
• One excellent example, not multiple variations
• Strategic comments only where they add architectural value
• Omit obvious Vitest patterns (standard beforeEach setup)

Before (863 words):

// Complete implementation with all details
const manualCounts = {
  total: links.length,
  valid: links.filter(link => link.validation.status === "valid").length,
  errors: links.filter(link => link.validation.status === "error").length,
  warnings: links.filter(link => link.validation.status === "warning").length
};

After (320 words):

// MEDIUM-IMPLEMENTATION abstraction
const manualCounts = {
  total: links.length,
  valid: /* count links where validation.status === "valid" */,
  errors: /* count where status === "error" */,
  warnings: /* count where status === "warning" */
};

Red Flags - STOP and Add Abstraction

If your test pseudocode has any of these, it's too detailed:

• ❌ Complete filter/map/reduce implementations
• ❌ Actual lambda expressions in code
• ❌ No placeholder comments for logic
• ❌ No Research/Fixture/Verification strategic comments
• ❌ Using implementation comment taxonomy (Boundary instead of Fixture)
• ❌ Complete object construction with all parameters
• ❌ More than 500 words for a single test example

All of these mean: Add placeholder comments and strategic guidance now.

Resisting Pressure for Complete Implementations

You will face pressure to provide complete implementations instead of MEDIUM-IMPLEMENTATION abstraction. Resist these rationalizations:

When asked for complete implementations:

1. Acknowledge the concern (time pressure, clarity needs, etc.)
2. Explain MEDIUM-IMPLEMENTATION abstraction purpose (learning, token efficiency)
3. Provide pseudocode following skill guidelines
4. If they insist on complete code, redirect to actual test files in repository (don't write it)

Never rationalize:

• "I'll make it complete to be helpful"
• "This one time won't hurt"
• "They're senior, they must know better"
• "The skill allows complete code in some cases" (it doesn't)

Common Mistakes

When Strategic Comments Add Value

Use strategic comments when:

• Test crosses integration boundaries (real vs mocked)
• Developer needs to research patterns (fixtures, DI setup)
• Verification strategy matters (what's being tested, why)
• Test structure pattern is non-obvious (Given-When-Then, AAA)
• Edge cases need explanation (illegal state prevention)

Don't overuse:

// ❌ Too many strategic comments
// Pattern: Array access
const link = links[0];

// ✅ Only when it adds value
// Verification: Single object provides both structure and validation (no correlation)
const link = links[0];

Real-World Impact

Before (baseline test result):

• Complete implementations (~860 words)
• Wrong strategic comment taxonomy (Boundary/Integration)
• No Research markers for patterns to investigate
• Token inefficient for user stories

After (with test pseudocode skill):

• MEDIUM-IMPLEMENTATION abstraction (~300 words)
• Test-specific taxonomy (Research/Fixture/Verification)
• Clear guidance on what to research and decide
• 60% token reduction for user stories

Developers can implement faster because they understand WHAT to test, WHY it matters, WHAT to research, and WHERE integration boundaries are - without being given complete implementations that skip learning.

Complete Example

// tools/citation-manager/test/integration/citation-validator-enrichment.test.js
import { /* Vitest test functions */ } from "vitest";
import { /* real system dependencies */ } from "...";

describe("CitationValidator Validation Enrichment Pattern", () => {
  let validator;
  let testFixturePath;

  beforeEach(() => {
    // Research: Vitest fixture patterns for isolation
    // Integration: Real components with DI (no mocks)
    const parser = /* new MarkdownParser with real fs */;
    const cache = /* new ParsedFileCache(parser) */;
    validator = /* new CitationValidator(cache, null) */;

    // Fixture: Real file with mixed valid/invalid links
    testFixturePath = /* resolve fixture path */;
  });

  it("should return ValidationResult with summary and enriched links", async () => {
    // Given: Real markdown file with citations
    // When: Validate file using enrichment pattern
    const result = /* await validator.validateFile(testFixturePath) */;

    // Then: Result has correct structure
    // Verification: New contract with summary + links (not separate results)
    expect(result).toHaveProperty("summary");
    expect(result).toHaveProperty("links");
    expect(result).not.toHaveProperty("results"); // OLD contract removed
  });

  it("should enrich valid LinkObjects with validation status", async () => {
    // Given: File with valid citations
    // When: Validation completes
    const { links } = /* await validator.validateFile(...) */;

    // Then: Valid links enriched with status="valid"
    // Verification: Valid state has no error/suggestion properties
    const validLink = /* links.find(link => link has valid target) */;
    expect(validLink).toHaveProperty("validation");
    expect(validLink.validation.status).toBe("valid");
    expect(validLink.validation).not.toHaveProperty("error");
  });

  it("should derive summary counts from enriched links", async () => {
    // Given: File with 3 valid, 2 error, 1 warning links
    // When: Validation completes
    const { summary, links } = /* await validator.validateFile(...) */;

    // Then: Summary matches link.validation.status counts
    // Pattern: Aggregate from links array to verify summary derivation
    const manualCounts = {
      total: links.length,
      valid: /* count links where validation.status === "valid" */,
      errors: /* count links where validation.status === "error" */,
      warnings: /* count links where validation.status === "warning" */
    };

    // Decision: Verify summary derives FROM links (directionality matters)
    expect(summary.total).toBe(manualCounts.total);
    expect(summary.valid).toBe(manualCounts.valid);
    expect(summary.errors).toBe(manualCounts.errors);
  });
});