feat: add nofix language tag to skip code blocks (#5)

Add support for `nofix` and `*-nofix` language tags to prevent boxfix
from processing code blocks. This is useful for documentation that
needs to show intentionally broken diagrams as examples.

- Skip code blocks with `nofix` or `*-nofix` (e.g., `text-nofix`)
- Add "before" example files showing broken LLM output
- Update README with vibecoded section and nofix documentation
- Add tests for the new behavior

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: kmelve

README.md

@@ -2,7 +2,7 @@
 
 LLMs generate ASCII diagrams with broken borders. This fixes them.
 
-```
+```nofix
 Before                          After
 ┌─────────────────────┐         ┌─────────────────────┐
 │ Component A        │    →     │ Component A         │
@@ -14,7 +14,7 @@ Before                          After
 
 LLMs generate ASCII diagrams with misaligned right borders. The top and bottom boundary lines (`┌───┐`, `└───┘`) are usually correct because they're repetitive patterns. But content lines with variable text end up short:
 
-```
+```nofix
 ┌─────────────────────────┐
 │ This line is too short│   ← Right border doesn't align
 │ API Gateway           │   ← Same problem here
@@ -102,7 +102,7 @@ boxfix doc1.md doc2.md --in-place
 
 The key insight: **boundary lines are reliable, content lines aren't**.
 
-```
+```nofix
 ┌─────────────────────┐  ← Boundary: LLMs get this right (repetitive)
 │ Content here       │   ← Content: LLMs mess this up (variable)
 │ More content       │   ← Content: Same problem
@@ -138,7 +138,7 @@ The key insight: **boundary lines are reliable, content lines aren't**.
 ```
 ┌─────────────────┐
 │ ┌─────────────┐ │
-│ │ Inner      │  │
+│ │ Inner       │ │
 │ └─────────────┘ │
 └─────────────────┘
 ```
@@ -149,6 +149,7 @@ The key insight: **boundary lines are reliable, content lines aren't**.
 - Lines without border characters
 - Already-aligned diagrams
 - Non-diagram code blocks
+- Code blocks with `nofix` or `*-nofix` language tag (e.g., ` ```nofix ` or ` ```text-nofix `)
 
 ## Programmatic API
 
@@ -339,6 +340,10 @@ If your diagram has content that overflows the boundaries, you'll need to either
 
 Boundary expansion is planned for a future release.
 
+## Vibecoded
+
+This entire library was built with [Claude Code](https://claude.ai/code) and Claude Opus 4.5. Every line of code, test, and documentation was generated through AI-assisted development.
+
 ## License
 
 MIT

examples/README.md

@@ -2,14 +2,12 @@
 
 This directory contains examples of properly aligned diagrams that demonstrate boxfix output.
 
-> **Note:** This repository has a Claude Code hook that automatically runs boxfix on markdown files. This means any intentionally misaligned "Before" examples get auto-fixed. The examples below show what boxfix produces, and inline comparisons show what it fixes.
-
 ## What Gets Fixed
 
 boxfix pads short content lines to match boundary widths. Here's what broken input looks like vs fixed output:
 
 **Broken (what LLMs often generate):**
-```
+```nofix
 ┌──────────────┐      ← boundary is 16 chars wide
 │ Short│               ← content line is only 8 chars (missing padding)
 │ Also short│          ← another short line
@@ -28,13 +26,15 @@ The boundary lines (`┌───┐`, `└───┘`) are the reference widt
 
 ## Examples
 
-| File | Description |
-|------|-------------|
-| [`simple-box.md`](./simple-box.md) | Single box with content lines |
-| [`nested-boxes.md`](./nested-boxes.md) | Boxes within boxes |
-| [`multiple-boxes.md`](./multiple-boxes.md) | Several boxes in one diagram |
-| [`ascii-style.md`](./ascii-style.md) | ASCII `+---+` style boxes |
-| [`architecture.md`](./architecture.md) | Complex architecture diagram |
+Each example has a `.before.md` version showing typical broken LLM output and a fixed version:
+
+| Before (broken) | After (fixed) | Description |
+|-----------------|---------------|-------------|
+| [`simple-box.before.md`](./simple-box.before.md) | [`simple-box.md`](./simple-box.md) | Single box with content lines |
+| [`nested-boxes.before.md`](./nested-boxes.before.md) | [`nested-boxes.md`](./nested-boxes.md) | Boxes within boxes |
+| [`multiple-boxes.before.md`](./multiple-boxes.before.md) | [`multiple-boxes.md`](./multiple-boxes.md) | Several boxes in one diagram |
+| [`ascii-style.before.md`](./ascii-style.before.md) | [`ascii-style.md`](./ascii-style.md) | ASCII `+---+` style boxes |
+| [`architecture.before.md`](./architecture.before.md) | [`architecture.md`](./architecture.md) | Complex architecture diagram |
 
 ## Running boxfix
 
@@ -58,18 +58,14 @@ npx boxfix --check examples/*.md
 
 ## Testing with Broken Input
 
-To test boxfix with actual broken diagrams, create a test file outside this repo or disable the hook temporarily:
+The `.before.md` files use the `nofix` language tag to preserve broken diagrams:
 
-```bash
-# Create a test file with broken diagram
-cat > /tmp/test.md << 'EOF'
-```
+````markdown
+```nofix
 ┌──────────────┐
-│ Short│
+│ Short        │
 └──────────────┘
 ```
-EOF
+````
 
-# Run boxfix
-npx boxfix /tmp/test.md
-```
+Code blocks with `nofix` or `*-nofix` language tags are skipped by boxfix.

examples/architecture.before.md

@@ -0,0 +1,28 @@
+# Architecture Diagram (Before)
+
+A complex architecture diagram with misaligned content throughout.
+
+```nofix
+┌─────────────────────────────────────────────────────────────────┐
+│  Landing Page A                    Landing Page B              │
+│  ┌──────────────────────┐         ┌──────────────────────────┐ │
+│  │ content[]           │          │ content[]               │  │
+│  │  ├─ heroPageBlock   │          │  ├─ featureSpotlight    │  │
+│  │  ├─ reference ───────┼────┬────┼──┤ reference ────────────┤ │
+│  │  └─ articlePageBlock│     │    │  └─ quotePageBlock      │  │
+│  └──────────────────────┘    │    └──────────────────────────┘ │
+└──────────────────────────────┼──────────────────────────────────┘
+                               │
+                               ▼
+                    ┌────────────────────────┐
+                    │  reusablePageBlock    │
+                    │  (document)           │
+                    │                       │
+                    │  title: "Shared CTA" │
+                    │  invertColor: false  │
+                    │  content[0]:         │
+                    │    callToActionBlock │
+                    └────────────────────────┘
+```
+
+Multiple nested boxes with varying content line widths. `boxfix` handles the complexity.

examples/ascii-style.before.md

@@ -0,0 +1,20 @@
+# ASCII Style Boxes (Before)
+
+Classic ASCII art with misaligned content lines.
+
+```nofix
++------------------------+
+| Database Connection   |
+| Host: localhost       |
+| Port: 5432|
++------------------------+
+        |
+        v
++------------------------+
+| Connection Pool|
+| Max: 10       |
+| Timeout: 30s  |
++------------------------+
+```
+
+Content lines vary in length. Run `boxfix` to align them to the 26-character boundary.

examples/multiple-boxes.before.md

@@ -0,0 +1,20 @@
+# Multiple Boxes (Before)
+
+Multiple boxes in the same diagram with misaligned content.
+
+```nofix
+┌──────────────┐    ┌──────────────┐    ┌──────────────┐
+│ Service A   │     │ Service B   │     │ Service C   │
+│ Port 3000│        │ Port 3001│        │ Port 3002│
+└──────────────┘    └──────────────┘    └──────────────┘
+       │                  │                            │
+       └──────────────────┼───────────────────┘
+                          │
+                          ▼
+                 ┌────────────────┐
+                 │ Load Balancer│
+                 │ nginx:latest│
+                 └────────────────┘
+```
+
+Each box has content lines that don't match their boundary widths. Run `boxfix` to align.

examples/nested-boxes.before.md

@@ -0,0 +1,22 @@
+# Nested Boxes (Before)
+
+Boxes within boxes - each with misaligned content.
+
+```nofix
+┌───────────────────────────────┐
+│ Outer Container              │
+│                            │
+│  ┌─────────────────────┐     │
+│  │ Inner Box          │      │
+│  │ with content│             │
+│  └─────────────────────┘     │
+│                            │
+│  ┌─────────────────────┐     │
+│  │ Another Inner│            │
+│  │ More content       │      │
+│  └─────────────────────┘     │
+│                            │
+└───────────────────────────────┘
+```
+
+Both outer and inner box content lines need padding. `boxfix` handles nested boxes correctly.

examples/simple-box.before.md

@@ -0,0 +1,14 @@
+# Simple Box (Before)
+
+A single box with misaligned content lines - typical LLM output.
+
+```nofix
+┌────────────────────────┐
+│ User Authentication   │
+│ Service│
+│                     │
+│ Handles login/logout│
+└────────────────────────┘
+```
+
+Content lines are shorter than the 26-character boundary width. Run `boxfix` to fix.

src/markdown.ts

@@ -47,6 +47,16 @@ export function boxfixMarkdown(markdown: string): BoxfixResult {
   let totalStats = emptyStats();
 
   for (const block of blocks) {
+    // Skip blocks marked with nofix language tag
+    if (block.language === "nofix" || block.language?.endsWith("-nofix")) {
+      totalStats = mergeStats(totalStats, {
+        linesFixed: 0,
+        blocksProcessed: 1,
+        diagramsFound: 0,
+      });
+      continue;
+    }
+
     // Check if this code block contains a diagram
     if (!isDiagram(block.content)) {
       totalStats = mergeStats(totalStats, {

test/boxfix.test.ts

@@ -351,6 +351,29 @@ const x = 1;
     expect(result.stats.blocksProcessed).toBe(1);
   });
 
+  it("skips code blocks with nofix language tag", () => {
+    const input = `\`\`\`nofix
+┌───┐
+│ x│
+└───┘
+\`\`\``;
+    const result = boxfixMarkdown(input);
+    expect(result.fixed).toBe(input);
+    expect(result.stats.linesFixed).toBe(0);
+    expect(result.stats.diagramsFound).toBe(0);
+  });
+
+  it("skips code blocks with -nofix suffix", () => {
+    const input = `\`\`\`text-nofix
+┌───┐
+│ x│
+└───┘
+\`\`\``;
+    const result = boxfixMarkdown(input);
+    expect(result.fixed).toBe(input);
+    expect(result.stats.linesFixed).toBe(0);
+  });
+
   it("handles multiple code blocks", () => {
     const input = `\`\`\`
 ┌───┐