Gitignore Generator

What is a .gitignore file?

A .gitignore file lists patterns Git should ignore — typically build artifacts, OS metadata, IDE caches, dependency directories, and secrets. Patterns follow gitignore glob syntax (*.log, build/, !keep-this.log) and apply per directory. Every Git repository should ship one to keep clones reproducible and prevent leaking environment-specific noise.

Common Stack Combinations

• Full-stack JavaScript: Node + Nextjs + macOS + JetBrains
• Python data project: Python + macOS + VisualStudioCode
• Mobile native: Android + Java + Gradle + JetBrains + macOS
• Static site: Node + Jekyll + macOS + VisualStudioCode
• Go service: Go + macOS + VisualStudioCode + JetBrains

How merging works

Selected templates are sorted alphabetically and concatenated. For each template we emit a ### Name.gitignore header so you can trace which rules came from where. Identical rule lines across templates are dropped after the first appearance, but comments and blank lines are kept verbatim. Custom rules go last under ### Custom additions. The output starts with a small attribution header pointing back to ZeroTool and the github/gitignore source — remove it freely if you prefer a clean file.

Why a curated bundle

Crawling github/gitignore at request time would add network latency and rate-limit exposure. We snapshot the repository at build time, dedupe IDs, and ship the result as a single TypeScript module — predictable, auditable, and zero runtime dependencies. Refreshing pulls a new snapshot from upstream and replaces the bundle in one commit.

Example: Node + macOS + JetBrains + VS Code

Tick JetBrains, macOS, Node and VisualStudioCode, then add three custom lines: node_modules/, .env.local and coverage-html/. The output is 313 lines: the attribution header, the four templates in alphabetical order (### JetBrains.gitignore first), and a ### Custom additions block that contains only .env.local and coverage-html/. The custom node_modules/ line was dropped because the Node template already has the identical line.

.env.local stayed even though the Node template’s .env.* already matches it. Deduplication compares the trimmed text of each line, not what the pattern matches.

Syntax Pitfalls, Checked with Git

With this .gitignore, git check-ignore -v (Git 2.56) reports:

logs/
!logs/keep.log
docs/*.pdf
build/
/secret.txt

• logs/keep.log is still ignored by logs/. Git does not look inside an excluded directory, so the negation never applies (gitignore documentation). Write logs/* instead of logs/ if you need the exception.
• docs/*.pdf ignores docs/a.pdf but not docs/notes/old.pdf: a slash in the middle anchors the pattern to the directory of the .gitignore file, and * does not cross /.
• build/ matches build/ and src/build/ at any depth, but only directories.
• /secret.txt matches the root file only; src/secret.txt is not ignored.

Files That Are Already Tracked

A new rule does not untrack files Git already tracks. Remove them from the index and commit; the files stay on disk:

git rm -r --cached node_modules/
git commit -m "Stop tracking node_modules"

This does not remove the files from earlier commits. If a secret was committed, rotate it; rewriting history (for example with git filter-repo) needs a force-push and fresh clones.

Limits

• The bundle has 237 templates: 162 from the root of github/gitignore (languages and frameworks) and 75 from Global/ (editors, operating systems, tools). Templates under community/ are not included.
• The templates are a snapshot taken when the bundle was last refreshed. Changes merged upstream after that appear only after the next refresh.
• Deduplication removes repeated identical lines across the whole file. It does not merge equivalent patterns such as node_modules and node_modules/.