1 files changed, 68 insertions, 0 deletions
diff --git a/tests/unit/grammar/test_helper_test.go b/tests/unit/grammar/test_helper_test.go
new file mode 100644
index 0000000..546d2c1
--- /dev/null
+++ b/tests/unit/grammar/test_helper_test.go
@@ -0,0 +1,68 @@
+package grammar
+
+import (
+	"testing"
+
+	"urubu/grammar/symbol"
+)
+
+type testSymbolGenerator func(text string) symbol.Symbol
+
+func newTestSymbolGenerator(t *testing.T, symTab *symbol.SymbolTableReader) testSymbolGenerator {
+	return func(text string) symbol.Symbol {
+		t.Helper()
+
+		sym, ok := symTab.ToSymbol(text)
+		if !ok {
+			t.Fatalf("symbol was not found: %v", text)
+		}
+		return sym
+	}
+}
+
+type testProductionGenerator func(lhs string, rhs ...string) *production
+
+func newTestProductionGenerator(t *testing.T, genSym testSymbolGenerator) testProductionGenerator {
+	return func(lhs string, rhs ...string) *production {
+		t.Helper()
+
+		rhsSym := []symbol.Symbol{}
+		for _, text := range rhs {
+			rhsSym = append(rhsSym, genSym(text))
+		}
+		prod, err := newProduction(genSym(lhs), rhsSym)
+		if err != nil {
+			t.Fatalf("failed to create a production: %v", err)
+		}
+
+		return prod
+	}
+}
+
+type testLR0ItemGenerator func(lhs string, dot int, rhs ...string) *lrItem
+
+func newTestLR0ItemGenerator(t *testing.T, genProd testProductionGenerator) testLR0ItemGenerator {
+	return func(lhs string, dot int, rhs ...string) *lrItem {
+		t.Helper()
+
+		prod := genProd(lhs, rhs...)
+		item, err := newLR0Item(prod, dot)
+		if err != nil {
+			t.Fatalf("failed to create a LR0 item: %v", err)
+		}
+
+		return item
+	}
+}
+
+func withLookAhead(item *lrItem, lookAhead ...symbol.Symbol) *lrItem {
+	if item.lookAhead.symbols == nil {
+		item.lookAhead.symbols = map[symbol.Symbol]struct{}{}
+	}
+
+	for _, a := range lookAhead {
+		item.lookAhead.symbols[a] = struct{}{}
+	}
+
+	return item
+}