Code Confidence Map

Code Confidence Map

Helps AI agents answer a core question: "If this code breaks tomorrow, how well-equipped are we to understand and fix it?"

This is NOT a linter or code quality tool. It measures comprehensibility risk — the gap between code complexity and human understanding. The AI's unique advantage over static analysis tools is semantic judgment: it can tell that processData does 5 unrelated things, that tests only cover happy paths, or that // don't touch this is a red flag.

When to Use This Skill

Use this skill when the user:

• Asks about code confidence, risk, or maintainability
• Says "is this code safe to change?" or "how risky is this module?"
• Is onboarding to a new codebase and wants to understand the landscape
• Wants to know where the tech debt or weak spots are
• Asks "which parts of the codebase are well-tested?"
• Says "scan this directory" or "check this file's health"
• Is planning a refactor and wants to assess risk first
• Asks about code quality, code health, or how solid a module is

Core Concept: What "Confidence" Means

Confidence is the answer to: "If something goes wrong here, can we understand and fix it?"

It is NOT:

• A judgment on code quality (LOW confidence is a risk signal, not a verdict)
• A measure of cleverness or elegance
• An indicator of who wrote the code or when

Confidence levels:

Do NOT use percentages (e.g., "73.2%"). They imply false precision for what is fundamentally a judgment call.

Overall level rule: The overall confidence level equals the lowest dimension level. If any single dimension is LOW, the overall is LOW — one critical gap is enough to make code risky to work with.

What We Explicitly Do NOT Measure

• Time since last edit — Stable code is fine. Code that hasn't been touched in years may be the most reliable in the project.
• Lines of code as a standalone metric — More code does not mean worse code.
• Number of contributors — Team dynamics vary too much to draw conclusions.
• Whether code was AI-generated — Irrelevant. What matters is whether the code is understood, regardless of who or what wrote it.

Confidence Dimensions

Core Dimensions (4)

These are evaluated for every file in Phase 2 / Single File Mode:

1. Test Safety Net

Are there tests? Do they test the right things?

• Read the test file(s) for the target module
• Check: do tests cover error paths and edge cases, or only happy paths?
• Check: are tests meaningful (not just expect(true).toBe(true))?
• A file with no test file at all is an immediate risk signal

Why it matters: Tests are executable documentation of intent. If there are no tests, nobody has formally defined what this code is supposed to do.

2. Self-Expressed Uncertainty

Does the code itself say "I'm not confident"?

Look for these markers (via grep or reading the file):

Why it matters: The code is literally telling you where the risk is.

3. Comprehensibility

Can a newcomer understand this code?

This requires reading the code and making a semantic judgment:

• Naming quality: Are variables, functions, and classes named descriptively? Or are there names like data, temp, x, processStuff?
• Comment-to-complexity ratio: Complex logic (regex, algorithms, state machines) should have proportionally more comments. Simple code needs fewer.
• Function size and nesting: Functions over ~50 lines or with 4+ levels of nesting are harder to follow.
• Single responsibility: Does each function/module do one thing, or is it a grab-bag?

Why it matters: If nobody can read it, nobody can fix it.

4. Error Handling

When things go wrong, do we get useful information?

• Empty catch blocks: Errors caught but silently swallowed — the worst pattern
• Generic error messages: throw new Error("failed") gives zero debugging context
• Unhandled edge cases: What happens with null, undefined, empty arrays, concurrent access?
• Error propagation: Are errors properly propagated or lost in the call chain?

Why it matters: Bad error handling turns a 5-minute fix into a 5-hour hunt.

Optional Dimension (1)

5. Dependency Risk (project-level only)

Are we building on shaky ground?

This dimension is only evaluated when scanning at the project level (not per-file). Read package.json and check:

• Floating versions of critical dependencies (e.g., "*" or ">= 1.0.0")
• Known deprecated packages (based on AI training knowledge)

Limitations: Cannot check npm for maintenance status (requires network). Cannot assess per-file dependency risk. Use only as supplementary information.

Interaction Strategy

Scope: Clear → Start Immediately, Ambiguous → Confirm First

Scan Workflow

Single File Mode

When the target is a single file, skip Phase 1 and go directly into deep analysis:

1. Read the target source file
2. Find and read the corresponding test file (foo.test.ts or foo.spec.ts)
3. Grep the file for uncertainty markers
4. Evaluate the file against the 4 core dimensions
5. Output a single-file confidence report

Directory Scan Mode

Phase 1: Quick Overview (low cost, no file content read)

Phase 1 only runs command-line tools. It does NOT read any source file contents. Use recursive commands to support nested directories:

# 1. Find source files (exclude test files)
find <target>/ -name "*.ts" ! -name "*.test.ts" ! -name "*.spec.ts"

# 2. Find test files
find <target>/ -name "*.test.ts" -o -name "*.spec.ts"

# 3. Grep uncertainty markers across all source files
grep -rEc "TODO|FIXME|HACK" <target>/ --include="*.ts" --exclude="*.test.ts" --exclude="*.spec.ts"
grep -rEc "@ts-ignore|eslint-disable" <target>/ --include="*.ts" --exclude="*.test.ts" --exclude="*.spec.ts"

Present the results as an overview table:

Quick Scan: src/core/ (8 source files)

| File              | Tests | Markers | Bypasses |
| ----------------- | ----- | ------- | -------- |
| config-loader.ts  | Y     | 0       | 0        |
| lock-manager.ts   | Y     | 0       | 0        |
| skill-parser.ts   | Y     | 0       | 0        |
| cache-manager.ts  | Y     | 1       | 0        |
| agent-registry.ts | Y     | 0       | 0        |
| skill-manager.ts  | Y     | 0       | 0        |
| installer.ts      | Y     | 2       | 0        |
| git-resolver.ts   | Y     | 3       | 1        |

Suggested for deep analysis:
  1. git-resolver.ts — 3 unresolved markers + 1 type bypass
  2. installer.ts — 2 unresolved markers

The remaining 6 files have tests and no obvious markers.
Which files to analyze? All / Suggested only / Pick your own?

Phase 1 Suggestion Rules

The suggestion list is based on 3 reliable signals (highest priority first):

1. No test file exists → suggest for deep analysis
   • Exclusion rule (by filename, without reading content): files named types.ts, type.ts, files under a types/ directory, and standalone index.ts files are excluded. This heuristic is imperfect but reasonable without reading file content.
2. Uncertainty markers >= 2 → suggest for deep analysis (TODO / FIXME / HACK)
3. Type/rule bypasses >= 1 → suggest for deep analysis (@ts-ignore / eslint-disable)

Files that don't match any of the above are NOT included in the suggestion list, but the user can still choose to analyze them manually.

Phase 2: Deep Analysis (after user chooses)

After the user selects which files to analyze, read each source file and its corresponding test file. Evaluate against the 4 core dimensions. Generate a confidence report with prioritized action items.

Report Formats

Single File Report

Code Confidence: src/core/git-resolver.ts
============================================
Level: LOW

Dimensions:
  Test Safety Net:         MEDIUM — Tests exist but only cover happy paths;
                           missing edge cases for SSH URLs and subgroups
  Self-Expressed Uncertainty: LOW — 3 TODOs (lines 45, 89, 112) + 1 @ts-ignore
  Comprehensibility:       MEDIUM — Regex-heavy but annotated with comments;
                           function naming is clear
  Error Handling:          LOW — Empty catch block on line 78;
                           error message on line 156 lacks context

Action Items:
  1. [HIGH IMPACT] Add edge-case tests for SSH URL parsing
  2. [HIGH IMPACT] Resolve TODO on line 45: "handle gitlab subgroups"
  3. [MEDIUM]      Line 78 empty catch — add meaningful error handling
                   or a comment explaining why the error is ignored

Directory Scan Report (Phase 2)

Code Confidence Map
===================
Scope: src/core/
Phase 1 overview: 8 files (6 clean, 2 suggested for deep analysis)
Phase 2 analyzed: 2 files

| Module          | Level  | Key Finding                              |
| --------------- | ------ | ---------------------------------------- |
| git-resolver.ts | LOW    | 3 TODOs, regex-heavy, insufficient tests |
| installer.ts    | MEDIUM | High complexity, tests miss error paths  |

Action Items (prioritized):
  1. [HIGH IMPACT] git-resolver.ts — Add tests for SSH URL edge cases
  2. [HIGH IMPACT] git-resolver.ts — Resolve 3 TODOs (lines 45, 89, 112)
  3. [MEDIUM]      installer.ts — Add error-path tests for symlink failures

Not analyzed (6 files):
  config-loader.ts, lock-manager.ts, skill-parser.ts,
  cache-manager.ts, agent-registry.ts, skill-manager.ts
  — All have tests and no obvious markers (no risk signals in Phase 1)

Examples

Example 1: Single File Assessment

User: "Is this file safe to change?" (while editing src/core/installer.ts)

Agent:
1. Reads src/core/installer.ts
2. Finds and reads src/core/installer.test.ts
3. Greps for uncertainty markers: 2 TODOs found
4. Evaluates 4 dimensions
5. Reports:

   Code Confidence: src/core/installer.ts
   Level: MEDIUM

   Dimensions:
     Test Safety Net:         MEDIUM — Tests cover installation flows but
                              miss symlink failure and permission error paths
     Self-Expressed Uncertainty: MEDIUM — 2 TODOs (lines 89, 134)
     Comprehensibility:       HIGH — Clear function names, well-structured,
                              single responsibility per function
     Error Handling:          MEDIUM — Most errors caught but some error
                              messages could be more descriptive

   Action Items:
     1. [MEDIUM] Add tests for symlink creation failure scenarios
     2. [LOW]    Resolve TODO on line 89

   Overall: Reasonably safe to change. The main risk is untested error
   paths — consider adding error-path tests before making significant
   modifications.

Example 2: Directory Scan

User: "Scan src/core/ for confidence"

Agent:
1. Runs Phase 1 (find + grep, no file reads)
2. Presents overview table with 8 files
3. Suggests 2 files for deep analysis

User: "Just the suggested ones"

Agent:
4. Reads git-resolver.ts + git-resolver.test.ts
5. Reads installer.ts + installer.test.ts
6. Evaluates each against 4 dimensions
7. Presents the directory scan report with action items

Example 3: Ambiguous Request

User: "How's the code quality?"

Agent: "Do you want to scan the entire project, a specific directory,
or a single file? For example:
  - 'Scan src/core/' for the core module
  - 'Check src/cli/commands/' for CLI commands
  - Or name a specific file"

Limitations

This skill is honest about what it can and cannot do:

Can do:

• Detect the presence/absence of test files
• Count uncertainty markers (TODO, FIXME, HACK, @ts-ignore, eslint-disable)
• Read code and make semantic judgments about naming, complexity, and error handling
• Provide actionable recommendations

Cannot do:

• Measure actual test coverage percentages (requires instrumentation tools)
• Assess runtime behavior or performance
• Determine if team members actually understand the code (social/organizational knowledge)
• Detect deprecated dependencies reliably (limited to AI training knowledge)
• Guarantee consistency across separate conversations (each scan is independent)

Design choices:

• Confidence is HIGH / MEDIUM / LOW, never a percentage — to avoid false precision
• Phase 1 suggestions use only reliable signals (no test file, marker count, bypass count) — no speculative heuristics
• The user always decides which files to deep-analyze — the agent does not make that decision autonomously
• LOW confidence is a risk signal, not a quality judgment — sometimes low-confidence code is perfectly fine if it's not on a critical path