fix(lint): keep templ fixtures as templ generates them

.githooks/pre-commit

@@ -1,17 +1,20 @@
 #!/bin/sh
 # Pre-commit hook to run goimports, gofmt, go vet, staticcheck, and golangci-lint
 
-# Run goimports on all Go files
+# Run goimports on all Go files but generated ones: gsx (*.x.go) and templ
+# (*_templ.go) output must stay as the generator wrote it, since
+# structpages-lint maps a _templ.go to its .templ only when the file is
+# exactly what templ generates.
 echo "Running goimports..."
-find . -name "*.go" -not -name "*.x.go" -not -path "./vendor/*" -not -path "./.git/*" | xargs goimports -w
+find . -name "*.go" -not -name "*.x.go" -not -name "*_templ.go" -not -path "./vendor/*" -not -path "./.git/*" | xargs goimports -w
 if [ $? -ne 0 ]; then
     echo "goimports failed"
     exit 1
 fi
 
-# Run gofmt on all Go files
+# Run gofmt on all Go files but generated ones
 echo "Running gofmt..."
-find . -name "*.go" -not -name "*.x.go" -not -path "./vendor/*" -not -path "./.git/*" | xargs gofmt -w -s
+find . -name "*.go" -not -name "*.x.go" -not -name "*_templ.go" -not -path "./vendor/*" -not -path "./.git/*" | xargs gofmt -w -s
 if [ $? -ne 0 ]; then
     echo "gofmt failed"
     exit 1

.github/workflows/ci.yml

@@ -132,3 +132,18 @@ jobs:
         working-directory: ./examples/${{ matrix.example }}
         run: go test ./...
 
+  test-lint-tool:
+    name: Test tools/lint
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+
+      - name: Set up Go
+        uses: actions/setup-go@v5
+        with:
+          go-version: "1.26"
+
+      - name: Test
+        working-directory: ./tools/lint
+        run: go test ./...

docs/lint.md

@@ -183,9 +183,11 @@ The attribute is matched exactly:
   only if the result is byte-for-byte the `_templ.go` on disk. The one exception is the
   `// templ: version:` comment line, which may differ or be missing (`templ generate -include-version=false`): it
   is a comment, so it changes no code. If anything else differs (another
-  templ version that generates different code, `-include-timestamp`, a hand edit), the file's positions can't be
-  trusted, and its attributes are skipped by `region` without a finding. To have them checked, regenerate with
-  the templ version the linter is built with (the `github.com/a-h/templ` version in the linter's `go.mod`).
+  templ version that generates different code, `-include-timestamp`, a hand edit, or a formatter run over the
+  generated file: `goimports` regroups its imports), the file's positions can't be trusted, and its attributes are
+  skipped by `region` and `keyed` without a finding. To have them checked, regenerate with the templ version the
+  linter is built with (the `github.com/a-h/templ` version in the linter's `go.mod`), and leave `*_templ.go` out of
+  any `goimports` or `gofmt -s` run, as you would gsx's `*.x.go`.
 
 Limits:
 

tools/lint/templscan/exprattr_test.go

@@ -0,0 +1,30 @@
+package templscan
+
+import (
+	"errors"
+	"path/filepath"
+	"testing"
+)
+
+// The linter's templ fixtures are joined to their .templ only when the
+// _templ.go is exactly what templ generates, so a formatter run over one
+// (goimports regroups its imports) silently drops its findings.
+// stale.templ's _templ.go differs on purpose.
+func TestExprAttrs_fixturesAreTemplOutput(t *testing.T) {
+	files, err := filepath.Glob("../testdata/*/tapp/*.templ")
+	if err != nil || len(files) == 0 {
+		t.Fatalf("no .templ fixtures: %v", err)
+	}
+	for _, f := range files {
+		_, err := ExprAttrs(f)
+		switch {
+		case filepath.Base(f) == "stale.templ":
+			if !errors.Is(err, ErrStale) {
+				t.Errorf("%s: err = %v, want ErrStale", f, err)
+			}
+		case err != nil:
+			t.Errorf("%s: %v (commit a _templ.go exactly as `templ generate` writes it: "+
+				"no goimports, no gofmt -s)", f, err)
+		}
+	}
+}