feat: initial plan

pkg/format/format_test.go

@@ -0,0 +1,118 @@
+package format
+
+import (
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/hein/pgtidy/pkg/config"
+	"github.com/hein/pgtidy/pkg/lexer"
+	"github.com/hein/pgtidy/pkg/parser"
+)
+
+func format(src string) string {
+	return File(parser.Parse(src), config.Default())
+}
+
+func TestFormatHeaderGolden(t *testing.T) {
+	src := "--select * from dropall('resolvespec_login');\n" +
+		"create or replace function resolvespec_login(\n" +
+		"INOUT p_data jsonb, OUT p_success boolean, OUT p_error text)\n" +
+		"language plpgsql volatile security definer\n" +
+		"as $$\nbegin end;\n$$;\n"
+
+	want := "--select * from dropall('resolvespec_login');\n" +
+		"CREATE OR REPLACE FUNCTION resolvespec_login(\n" +
+		"   INOUT p_data jsonb\n" +
+		"  ,OUT p_success boolean\n" +
+		"  ,OUT p_error text\n" +
+		")\n" +
+		"LANGUAGE plpgsql\n" +
+		"VOLATILE\n" +
+		"SECURITY DEFINER\n" +
+		"AS\n" +
+		"$$\nbegin end;\n$$;\n"
+
+	got := format(src)
+	if got != want {
+		t.Errorf("header format mismatch\n--- got ---\n%s\n--- want ---\n%s", got, want)
+	}
+}
+
+func TestIdempotentSmall(t *testing.T) {
+	src := "create function f(a int,b text) returns void language sql as $$ select 1 $$;"
+	once := format(src)
+	twice := format(once)
+	if once != twice {
+		t.Errorf("not idempotent\n--- once ---\n%s\n--- twice ---\n%s", once, twice)
+	}
+}
+
+func TestCorpusIdempotentAndSafe(t *testing.T) {
+	dir := filepath.Join("..", "..", "testdata", "corpus")
+	entries, err := os.ReadDir(dir)
+	if err != nil {
+		t.Skipf("no corpus: %v", err)
+	}
+	var seen int
+	for _, e := range entries {
+		if e.IsDir() || !strings.HasSuffix(e.Name(), ".pgsql") {
+			continue
+		}
+		seen++
+		data, err := os.ReadFile(filepath.Join(dir, e.Name()))
+		if err != nil {
+			t.Fatal(err)
+		}
+		src := string(data)
+		once := format(src)
+		twice := format(once)
+		if once != twice {
+			t.Errorf("%s: not idempotent", e.Name())
+		}
+		if !semanticallyEqual(src, once) {
+			t.Errorf("%s: formatting changed semantics", e.Name())
+		}
+	}
+	if seen == 0 {
+		t.Skip("no corpus files")
+	}
+	t.Logf("formatted %d corpus files (idempotent + semantically equal)", seen)
+}
+
+// semanticallyEqual compares the non-trivia token streams of two sources,
+// treating unquoted identifiers/keywords case-insensitively and everything
+// else (strings, numbers, dollar bodies, operators, punctuation) exactly. This
+// validates that formatting changed only layout/casing, never meaning.
+func semanticallyEqual(a, b string) bool {
+	ta := significant(a)
+	tb := significant(b)
+	if len(ta) != len(tb) {
+		return false
+	}
+	for i := range ta {
+		if ta[i].Kind != tb[i].Kind {
+			return false
+		}
+		if ta[i].Kind == lexer.Ident {
+			if !strings.EqualFold(ta[i].Text, tb[i].Text) {
+				return false
+			}
+		} else if ta[i].Text != tb[i].Text {
+			return false
+		}
+	}
+	return true
+}
+
+func significant(src string) []lexer.Token {
+	var out []lexer.Token
+	for _, t := range lexer.Lex(src) {
+		if t.Kind == lexer.EOF || t.IsTrivia() {
+			continue
+		}
+		out = append(out, t)
+	}
+	return out
+}