Scope checks per package in a monorepo

Every rule in Straitjacket looks at one file at a time. Nothing compares a file against the rest of the tree, so a monorepo needs no boundary markers and no special mode — a scan from the root is just a scan of every file under it.

What a monorepo does want is different settings per package, and that falls out of how configuration is discovered.

One config per package#

Straitjacket looks for straitjacket.toml in the current directory and walks up to the filesystem root, using the first one it finds. So a package with its own file gets its own settings when you scan from inside it:

straitjacket.toml                  # repo-wide defaults
packages/web/straitjacket.toml     # stricter: the design system lives here
packages/legacy/straitjacket.toml  # looser: grandfathered

cd packages/web && straitjacket

That picks up packages/web/straitjacket.toml and never sees the root one. The files do not merge — the nearest config wins outright — so a package config should be complete rather than a delta.

# packages/legacy/straitjacket.toml
skip = ["motion", "inline-font"]
max-lines = 4000

Scanning the whole tree#

Run from the root and you get the root config for everything:

straitjacket

Per-package configs are not consulted in that pass — discovery starts from the working directory, not from each file. If you want each package checked under its own rules, scan them separately, which in CI is a matrix job or a loop:

for pkg in packages/*/; do (cd "$pkg" && straitjacket) || fail=1; done

Narrowing from the root#

For the common case — one root config, but only some directories worth scanning — set paths and skip the loop entirely:

# straitjacket.toml
paths = ["packages/web/src", "packages/api/src"]

Or pass them per-run:

straitjacket packages/web packages/api

Excluding by prefix#

Two rules take path prefixes directly, which is usually cleaner than carving up the scan:

file-size-exclude = ["packages/generated/", "notes/"]
todo-exclude = ["packages/legacy/"]

The suppression markers still cover the one-off exceptions that no amount of scoping should.