Merge branch 'fix/131-codegen-check-scope' into fix/quick-wins-batch

2026-08-19 14:08:13 -04:00
parent e454e4074b f714fe513d
commit 4f2f1827ab
2 changed files with 87 additions and 11 deletions
@@ -0,0 +1,81 @@
+#!/usr/bin/env bash
+#
+# Fails when `go generate ./...` would change something that is not staged.
+#
+# The obvious spelling of this is `go generate && git diff --name-only`,
+# which is what the hook used to be, and it answers the wrong question:
+# that diff is the *whole unstaged worktree*, so any unrelated edit — a
+# note, a plan document, the next commit's files sitting there while this
+# one lands — was reported as
+#
+#     Generated code is out of date. Run 'make generate' and stage the changes.
+#
+# Running `make generate` then does nothing, because nothing generated is
+# stale, and the message sends you looking for a codegen problem that does
+# not exist.  Splitting one piece of work into several commits is exactly
+# the shape that triggers it, so the workaround was a constraint on commit
+# order for no real reason.
+#
+# So the tree is snapshotted either side of the generators and only what
+# *moved across them* is reported.  That is deliberately not a list of
+# generated paths: sqlcgen, `*_templ.go` and `frontend/src/events.ts` are
+# today's answer, a fourth generator is one `//go:generate` line away, and
+# a path list is a second place to remember it — the same reasoning that
+# keeps staleshape.go parsing sql/schemas/ rather than restating it.
+#
+# Content, not names: a generated file that is *already* dirty and is then
+# rewritten further keeps its name in both snapshots and would otherwise
+# slip through.
+
+set -euo pipefail
+
+cd "$(dirname "$0")/.."
+
+# name + worktree blob hash for every file that differs from the index.
+# A file listed but absent (a deletion) hashes as "gone" rather than
+# aborting the pipeline.
+snapshot() {
+	git diff --name-only | while IFS= read -r f; do
+		if [ -f "$f" ]; then
+			printf '%s %s\n' "$f" "$(git hash-object -- "$f")"
+		else
+			printf '%s gone\n' "$f"
+		fi
+	done
+}
+
+# A brand-new generated file is not in either diff, because it is not
+# tracked at all — the same blind spot bindings-check.sh names.  Both
+# snapshots are taken before the generators run.
+before="$(snapshot)"
+before_untracked="$(git ls-files --others --exclude-standard)"
+
+go generate ./...
+
+after="$(snapshot)"
+after_untracked="$(git ls-files --others --exclude-standard)"
+
+# Symmetric difference, and the symmetry is the whole point.  Generation
+# can push a file *into* the unstaged set (it was current, now it is not)
+# or *out* of it (someone hand-edited generated output and the generator
+# put it back) — and the second is stale generated code just as much as
+# the first.  Comparing one direction only reports "current" for it,
+# which is the failure this script was written to stop.
+moved="$(comm -3 <(printf '%s\n' "$before" | sort) <(printf '%s\n' "$after" | sort) |
+	cut -d' ' -f1 | tr -d '\t' | sort -u | grep -v '^$' || true)"
+
+if [ -n "$moved" ]; then
+	echo "codegen-check: generated code is out of date." >&2
+	echo "Run 'make generate' and stage:" >&2
+	printf '  %s\n' $moved >&2
+	exit 1
+fi
+
+if [ "$after_untracked" != "$before_untracked" ]; then
+	echo "codegen-check: generation produced new files. Stage them:" >&2
+	comm -13 <(printf '%s\n' "$before_untracked" | sort) \
+		<(printf '%s\n' "$after_untracked" | sort) >&2
+	exit 1
+fi
+
+echo "codegen-check: generated code is current"