From 5e6eafef6450aedf6160f68e5539e5b77679c97e Mon Sep 17 00:00:00 2001
From: Brandon Dyck <brandon@dyck.us>
Date: Fri, 27 Sep 2024 10:40:18 -0600
Subject: [PATCH] Test Repeat success/failure

---
 parser_test.go                   | 18 ++++++++++++++++--
 test/{readerat.go => helpers.go} |  8 ++++++++
 2 files changed, 24 insertions(+), 2 deletions(-)
 rename test/{readerat.go => helpers.go} (85%)

diff --git a/parser_test.go b/parser_test.go
index 08251e6..6e44cac 100644
--- a/parser_test.go
+++ b/parser_test.go
@@ -138,8 +138,22 @@ func TestEnd(t *testing.T) {
 }
 
 func TestRepeat(t *testing.T) {
-	t.Run("fails when number of successes is less than minCount", Todo)
-	t.Run("succeeds when number of successes is greater than minCount", Todo)
+	t.Run("succeeds iff number of successes ≥ minCount", rapid.MakeCheck(func(t *rapid.T) {
+		const good byte = 'o'
+		const bad byte = 'x'
+		const maxParses = 100
+
+		minCount := rapid.IntRange(0, maxParses).Draw(t, "minCount")
+		successes := rapid.IntRange(0, maxParses).Draw(t, "successes")
+
+		input := append(ptest.SliceOfN(good, successes), bad)
+		p := gigaparsec.Repeat(minCount, gigaparsec.Match(good))
+		result, err := p(gigaparsec.MakeState(bytes.NewReader(input)))
+
+		must.NoError(t, err)
+		success, _, _ := result.Status()
+		test.EqOp(t, successes >= minCount, success, test.Sprint("expected successes ≥ minCount"))
+	}))
 	t.Run("consumes iff at least one application consumes", Todo)
 	t.Run("fails on error", Todo)
 	t.Run("position is unchanged on failure", Todo)
diff --git a/test/readerat.go b/test/helpers.go
similarity index 85%
rename from test/readerat.go
rename to test/helpers.go
index 0c57402..a47f22f 100644
--- a/test/readerat.go
+++ b/test/helpers.go
@@ -26,3 +26,11 @@ func ErrReaderAt(err error) io.ReaderAt {
 func StateIsAt[Input any](t test.T, s gigaparsec.State[Input], pos uint64) {
 	test.EqOp(t, pos, s.Pos(), test.Sprintf("expected parser state to be at position %d, got %d", pos, s.Pos()))
 }
+
+func SliceOfN[T any](value T, n int) []T {
+	s := make([]T, n)
+	for i := range s {
+		s[i] = value
+	}
+	return s
+}