whatcanGOwrong

go/pkg/mod/github.com/go-delve/liner@v1.2.3-0.20231231155935-4726ab1d7f62/line_test.go

@@ -0,0 +1,146 @@
+package liner
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+	"testing"
+)
+
+func TestAppend(t *testing.T) {
+	var s State
+	s.AppendHistory("foo")
+	s.AppendHistory("bar")
+
+	var out bytes.Buffer
+	num, err := s.WriteHistory(&out)
+	if err != nil {
+		t.Fatal("Unexpected error writing history", err)
+	}
+	if num != 2 {
+		t.Fatalf("Expected 2 history entries, got %d", num)
+	}
+
+	s.AppendHistory("baz")
+	num, err = s.WriteHistory(&out)
+	if err != nil {
+		t.Fatal("Unexpected error writing history", err)
+	}
+	if num != 3 {
+		t.Fatalf("Expected 3 history entries, got %d", num)
+	}
+
+	s.AppendHistory("baz")
+	num, err = s.WriteHistory(&out)
+	if err != nil {
+		t.Fatal("Unexpected error writing history", err)
+	}
+	if num != 3 {
+		t.Fatalf("Expected 3 history entries after duplicate append, got %d", num)
+	}
+
+	s.AppendHistory("baz")
+
+}
+
+func TestHistory(t *testing.T) {
+	input := `foo
+bar
+baz
+quux
+dingle`
+
+	var s State
+	num, err := s.ReadHistory(strings.NewReader(input))
+	if err != nil {
+		t.Fatal("Unexpected error reading history", err)
+	}
+	if num != 5 {
+		t.Fatal("Wrong number of history entries read")
+	}
+
+	var out bytes.Buffer
+	num, err = s.WriteHistory(&out)
+	if err != nil {
+		t.Fatal("Unexpected error writing history", err)
+	}
+	if num != 5 {
+		t.Fatal("Wrong number of history entries written")
+	}
+	if strings.TrimSpace(out.String()) != input {
+		t.Fatal("Round-trip failure")
+	}
+
+	// clear the history and re-write
+	s.ClearHistory()
+	num, err = s.WriteHistory(&out)
+	if err != nil {
+		t.Fatal("Unexpected error writing history", err)
+	}
+	if num != 0 {
+		t.Fatal("Wrong number of history entries written, expected none")
+	}
+	// Test reading with a trailing newline present
+	var s2 State
+	num, err = s2.ReadHistory(&out)
+	if err != nil {
+		t.Fatal("Unexpected error reading history the 2nd time", err)
+	}
+	if num != 5 {
+		t.Fatal("Wrong number of history entries read the 2nd time")
+	}
+
+	num, err = s.ReadHistory(strings.NewReader(input + "\n\xff"))
+	if err == nil {
+		t.Fatal("Unexpected success reading corrupted history", err)
+	}
+	if num != 5 {
+		t.Fatal("Wrong number of history entries read the 3rd time")
+	}
+}
+
+func TestColumns(t *testing.T) {
+	list := []string{"foo", "food", "This entry is quite a bit longer than the typical entry"}
+
+	output := []struct {
+		width, columns, rows, maxWidth int
+	}{
+		{80, 1, 3, len(list[2]) + 1},
+		{120, 2, 2, len(list[2]) + 1},
+		{800, 14, 1, 0},
+		{8, 1, 3, 7},
+	}
+
+	for i, o := range output {
+		col, row, max := calculateColumns(o.width, list)
+		if col != o.columns {
+			t.Fatalf("Wrong number of columns, %d != %d, in TestColumns %d\n", col, o.columns, i)
+		}
+		if row != o.rows {
+			t.Fatalf("Wrong number of rows, %d != %d, in TestColumns %d\n", row, o.rows, i)
+		}
+		if max != o.maxWidth {
+			t.Fatalf("Wrong column width, %d != %d, in TestColumns %d\n", max, o.maxWidth, i)
+		}
+	}
+}
+
+// This example demonstrates a way to retrieve the current
+// history buffer without using a file.
+func ExampleState_WriteHistory() {
+	var s State
+	s.AppendHistory("foo")
+	s.AppendHistory("bar")
+
+	buf := new(bytes.Buffer)
+	_, err := s.WriteHistory(buf)
+	if err == nil {
+		history := strings.Split(strings.TrimSpace(buf.String()), "\n")
+		for i, line := range history {
+			fmt.Println("History entry", i, ":", line)
+		}
+	}
+	// Output:
+	// History entry 0 : foo
+	// History entry 1 : bar
+}