git:20260814.b382b17 to git:20260826.ac7c2f1

---

name: browser4-fix-bug

description: "Fix bugs in code using a compile-test-fix loop: run the build/tests, read the error, locate the faulty lines, edit, and re-verify until green. Use when the user reports a build failure, test failure, crash, or asks to fix an error in Browser4 plugins, Kotlin, TS/JS, Python, or scripts."

allowed-tools: coding.shell coding.read coding.readLines coding.replace coding.replaceRegex coding.editLines coding.insertAfter coding.diff coding.changeSummary coding.revert coding.diagnostics coding.references coding.symbols coding.lspServers tab.eval tab.console

---

# browser4-fix-bug

Drive a bug from "it fails" to "it passes" with a disciplined compile-test-fix loop.

Never guess — read the actual error, make the smallest edit, and re-verify.

## When to Use

- User reports a build/compile failure or a failing test

- A plugin, skill script, JS, or shell script errors at runtime

- User says "fix this error", "the build is broken", "tests fail", "it crashes"

- LSP diagnostics (`coding.diagnostics`) report errors in a file

## Workflow

### 1. Reproduce — get the concrete error

```

coding.shell(command="mvn -pl <module> -am compile -DskipTests") # Kotlin/Maven

coding.shell(command="tsc --noEmit") # TS

coding.shell(command="python -m py_compile <file>.py") # Python

coding.shell(command="bash -n <file>.sh") # Bash

tab.eval(expression=<read the JS file>) + tab.console() # Browser JS

```

If LSP servers are available, prefer instant pre-checks first:

`coding.diagnostics(path=<file>)` — structured errors with line numbers.

### 2. Locate — read the failing code, not the whole file

```

coding.readLines(path=<file>, startLine=<line-8>, endLine=<line+8>)

coding.references(path=<file>, symbol=<suspected-symbol>) # impact check before edits

coding.diff(path=<file>) # what changed recently

```

### 3. Fix — smallest possible edit

| Symptom | Tool |

|---------|------|

| Wrong string | `coding.replace(path, oldStr, newStr)` |

| Pattern-based | `coding.replaceRegex(path, regex, replacement)` |

| Whole block | `coding.editLines(path, startLine, endLine, content)` |

| Add a line | `coding.insertAfter(path, anchor, content)` |

| Edit went wrong | `coding.revert(path)` then redo |

### 4. Verify — rerun the exact command from step 1

Loop 1→4 until green. **Do not** make multiple unrelated edits between verifications —

one fix, one check, so you always know which edit worked.

### 5. Report

Summarize: root cause (one line), fix (file:line), verification result

(build/test output tail). If the fix took more than 3 attempts, re-read the

error output carefully before continuing — do not fire-and-forget edits.

## Rules

1. **Read before you write.** Never edit a line you have not seen.

2. **One change per verify cycle.** Batch edits only after each is proven.

3. **Use diagnostics when available.** `coding.lspServers` tells you which

language servers are installed; prefer `coding.diagnostics` over a full build

for TS/JS/Python.

4. **Prefer editLines/insertAfter over replace** for block edits — less chance

of matching the wrong occurrence.

5. **Revert is cheap.** If an edit makes things worse, `coding.revert` restores

the pre-edit snapshot, then retry with a different approach.

6. **Stop and escalate** after 5 failed attempts — report the exact error and

your attempted fixes rather than degrading the code.

## Examples

```

User: 编译报错了，browser4-seo 插件 mvn compile 失败

Agent: 1. coding.shell(command="mvn -pl browser4-plugins/browser4-seo -am compile -DskipTests")

2. → error: SeoToolExecutor.kt:42 Unresolved reference 'foo'

3. coding.readLines(path="browser4-plugins/browser4-seo/src/main/kotlin/ai/platon/pulsar/seo/tools/SeoToolExecutor.kt",

startLine=34, endLine=50)

4. coding.replace(path=..., oldStr="foo", newStr="bar")

5. coding.shell(command="mvn -pl browser4-plugins/browser4-seo -am compile -DskipTests") → BUILD SUCCESS

6. 报告：根因 import 拼写；修复 SeoToolExecutor.kt:42；mvn compile 通过

```