From 0b243859fc9b184ec66228fd68c621ae4e3c6933 Mon Sep 17 00:00:00 2001
From: karitham <kar@karitham.dev>
Date: Sat, 22 Aug 2026 00:14:17 +0200
Subject: [PATCH] formatter: roundtrip the full tests/ corpus

The evernote, galaxy, and line-protocol fixtures were checked in
but referenced by no test. Feed every .thrift under tests/
through format -> reparse -> reformat and assert zero errors and
idempotency per file.
---
 formatter/corpus_test.go | 89 ++++++++++++++++++++++++++++++++++++++++
 1 file changed, 89 insertions(+)
 create mode 100644 formatter/corpus_test.go

diff --git a/formatter/corpus_test.go b/formatter/corpus_test.go
new file mode 100644
index 0000000..7fd6398
--- /dev/null
+++ b/formatter/corpus_test.go
@@ -0,0 +1,89 @@
+package formatter
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/karitham/thrift-ls/syntax"
+)
+
+// TestFormatRealWorldCorpus feeds every .thrift file under the repo's
+// tests/ directories through the format -> reparse -> reformat pipeline.
+// These are real-world IDLs (Evernote, Galaxy, line-protocol, lint
+// fixtures): shapes the hand-written format cases do not cover.
+//
+// Invariants per file:
+//   - the file parses with no errors (they are all valid IDLs)
+//   - its formatted output parses with no errors
+//   - formatting is idempotent: format(format(x)) == format(x)
+func TestFormatRealWorldCorpus(t *testing.T) {
+	roots := []string{
+		filepath.Join("..", "tests", "made-in-abyss"),
+		filepath.Join("..", "tests", "evernote-thrift"),
+		filepath.Join("..", "tests", "galaxy-thrift-api"),
+		filepath.Join("..", "tests", "line-protocol"),
+	}
+
+	files := make([]string, 0, 64)
+	for _, root := range roots {
+		err := filepath.WalkDir(root, func(path string, d os.DirEntry, err error) error {
+			if err != nil {
+				return err
+			}
+
+			if !d.IsDir() && strings.HasSuffix(path, ".thrift") {
+				files = append(files, path)
+			}
+
+			return nil
+		})
+		if err != nil {
+			t.Fatalf("walk %s: %v", root, err)
+		}
+	}
+
+	if len(files) == 0 {
+		t.Fatal("no corpus files found; tests/ missing?")
+	}
+
+	for _, path := range files {
+		t.Run(filepath.ToSlash(strings.TrimPrefix(path, ".."+string(filepath.Separator))), func(t *testing.T) {
+			src, err := os.ReadFile(path)
+			if err != nil {
+				t.Fatalf("read: %v", err)
+			}
+
+			doc := parseBytes(t, src)
+
+			formatted, ferr := Format(doc, DefaultOptions())
+			if ferr != nil {
+				t.Fatalf("format: %v", ferr)
+			}
+
+			reparsed := parseBytes(t, []byte(formatted))
+
+			again, ferr := Format(reparsed, DefaultOptions())
+			if ferr != nil {
+				t.Fatalf("reformat: %v", ferr)
+			}
+
+			if again != formatted {
+				t.Errorf("not idempotent\nfirst:\n%s\nsecond:\n%s", formatted, again)
+			}
+		})
+	}
+}
+
+// parseBytes parses src and fails the test on any hard parse error.
+func parseBytes(t *testing.T, src []byte) *syntax.Document {
+	t.Helper()
+
+	doc, errs := syntax.Parse(src)
+	if hasParseErrors(errs) {
+		t.Fatalf("unexpected parse errors: %v", errs)
+	}
+
+	return doc
+}
-- 
2.51.2