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package buffer
import (
"errors"
"os"
"path/filepath"
"testing"
)
func TestOpenReadsTheFile(t *testing.T) {
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "package main\n\nfunc main() {}\n")
b, err := Open(path)
if err != nil {
t.Fatalf("Open() error = %v", err)
}
if got := b.LineCount(); got != 3 {
t.Errorf("LineCount() = %d, want 3", got)
}
if got := b.Path(); got != path {
t.Errorf("Path() = %q, want %q", got, path)
}
if b.Modified() {
t.Error("a freshly opened buffer must not be modified")
}
if b.CanUndo() {
t.Error("opening a file must not leave anything to undo")
}
}
func TestOpenAMissingFileGivesAnEmptyBuffer(t *testing.T) {
path := filepath.Join(t.TempDir(), "new.go")
b, err := Open(path)
if err != nil {
t.Fatalf("Open() error = %v, want nil for a file that does not exist yet", err)
}
if got := b.LineCount(); got != 1 {
t.Errorf("LineCount() = %d, want 1", got)
}
if got := b.Path(); got != path {
t.Errorf("Path() = %q, want the requested path", got)
}
if b.Modified() {
t.Error("an empty new buffer must not be modified")
}
}
func TestOpenADirectoryFails(t *testing.T) {
if _, err := Open(t.TempDir()); err == nil {
t.Fatal("Open() error = nil, want a failure when the path is a directory")
}
}
func TestSaveWritesTheTextBack(t *testing.T) {
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "package main\n")
b, err := Open(path)
if err != nil {
t.Fatalf("Open() error = %v", err)
}
b.MoveBufferEnd()
b.Insert("\nfunc main() {}")
if err := b.Save(); err != nil {
t.Fatalf("Save() error = %v", err)
}
if b.Modified() {
t.Error("Save must clear the modified flag")
}
want := "package main\nfunc main() {}\n"
if got := readTestFile(t, path); got != want {
t.Errorf("file content = %q, want %q", got, want)
}
}
func TestSaveRoundTripsAnUnmodifiedFileByteForByte(t *testing.T) {
tests := []struct {
name string
content string
}{
{"unix endings", "a\nb\n"},
{"windows endings", "a\r\nb\r\n"},
{"no trailing newline", "a\nb"},
{"empty file", ""},
}
for _, tc := range tests {
t.Run(tc.name, func(t *testing.T) {
path := filepath.Join(t.TempDir(), "f.txt")
writeTestFile(t, path, tc.content)
b, err := Open(path)
if err != nil {
t.Fatalf("Open() error = %v", err)
}
if err := b.Save(); err != nil {
t.Fatalf("Save() error = %v", err)
}
if got := readTestFile(t, path); got != tc.content {
t.Errorf("file content = %q, want %q", got, tc.content)
}
})
}
}
func TestSaveWithoutAPathReportsErrNoPath(t *testing.T) {
b := NewFromString("orphan")
err := b.Save()
if !errors.Is(err, ErrNoPath) {
t.Errorf("Save() error = %v, want ErrNoPath", err)
}
}
func TestSaveAsAdoptsTheNewPath(t *testing.T) {
dir := t.TempDir()
path := filepath.Join(dir, "copy.go")
b := NewFromString("package main\n")
if err := b.SaveAs(path); err != nil {
t.Fatalf("SaveAs() error = %v", err)
}
if got := b.Path(); got != path {
t.Errorf("Path() = %q, want %q", got, path)
}
if got := readTestFile(t, path); got != "package main\n" {
t.Errorf("file content = %q", got)
}
if entries, _ := os.ReadDir(dir); len(entries) != 1 {
t.Errorf("the directory holds %d entries, want 1 — the temporary file must be gone", len(entries))
}
}
func TestSaveKeepsTheExistingFilePermissions(t *testing.T) {
path := filepath.Join(t.TempDir(), "script.go")
writeTestFile(t, path, "package main\n")
if err := os.Chmod(path, 0o640); err != nil {
t.Fatalf("Chmod() error = %v", err)
}
b, err := Open(path)
if err != nil {
t.Fatalf("Open() error = %v", err)
}
if err := b.Save(); err != nil {
t.Fatalf("Save() error = %v", err)
}
info, err := os.Stat(path)
if err != nil {
t.Fatalf("Stat() error = %v", err)
}
if got := info.Mode().Perm(); got != 0o640 {
t.Errorf("permissions = %o, want 640 — the atomic rename must not tighten them", got)
}
}
func TestSaveIntoAMissingDirectoryFails(t *testing.T) {
b := NewFromString("x")
err := b.SaveAs(filepath.Join(t.TempDir(), "nope", "f.go"))
if err == nil {
t.Fatal("SaveAs() error = nil, want a failure when the directory does not exist")
}
if b.Path() != "" {
t.Errorf("Path() = %q, want it left alone after a failed save", b.Path())
}
}
func TestModeOfFallsBackForAMissingFile(t *testing.T) {
if got := modeOf(filepath.Join(t.TempDir(), "absent")); got != defaultFileMode {
t.Errorf("modeOf(missing) = %o, want %o", got, defaultFileMode)
}
}
// writeTestFile creates a file with the given content, failing the test if it
// cannot.
func writeTestFile(t *testing.T, path, content string) {
t.Helper()
if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
t.Fatalf("writing %s: %v", path, err)
}
}
// readTestFile returns the content of a file, failing the test if it cannot.
func readTestFile(t *testing.T, path string) string {
t.Helper()
data, err := os.ReadFile(path)
if err != nil {
t.Fatalf("reading %s: %v", path, err)
}
return string(data)
}
func TestReloadPicksUpAChangeMadeOnDisk(t *testing.T) {
// What a formatter run from the Go menu leaves behind.
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "package main\n")
b, err := Open(path)
if err != nil {
t.Fatalf("Open() error = %v", err)
}
writeTestFile(t, path, "package main\n\nfunc main() {}\n")
changed, err := b.Reload()
if err != nil {
t.Fatalf("Reload() error = %v", err)
}
if !changed {
t.Error("Reload() reported no change for a file that was rewritten")
}
if got := b.Text(); got != "package main\n\nfunc main() {}\n" {
t.Errorf("the buffer holds %q", got)
}
if b.Modified() {
t.Error("a reloaded buffer reports itself modified")
}
}
func TestReloadReportsNoChangeWhenTheFileIsTheSame(t *testing.T) {
// A caller uses this to tell a file something rewrote from one it did not.
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "package main\n")
b, _ := Open(path)
changed, err := b.Reload()
if err != nil {
t.Fatalf("Reload() error = %v", err)
}
if changed {
t.Error("Reload() reported a change for a file nobody touched")
}
}
func TestReloadRefusesToThrowAwayUnsavedWork(t *testing.T) {
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "package main\n")
b, _ := Open(path)
b.Insert("// mine")
before := b.Text()
writeTestFile(t, path, "something else\n")
_, err := b.Reload()
if !errors.Is(err, ErrModified) {
t.Fatalf("Reload() error = %v, want ErrModified", err)
}
if got := b.Text(); got != before {
t.Errorf("the buffer was reloaded anyway: %q", got)
}
}
func TestReloadKeepsTheCursorWhereItWas(t *testing.T) {
// A formatter moves lines about; putting the cursor back at the top would
// lose the reader's place for no reason.
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "one\ntwo\nthree\n")
b, _ := Open(path)
b.SetCursor(Position{Line: 1, Col: 2})
if _, err := b.Reload(); err != nil {
t.Fatalf("Reload() error = %v", err)
}
writeTestFile(t, path, "one\nTWO!\nthree\n")
if _, err := b.Reload(); err != nil {
t.Fatalf("Reload() error = %v", err)
}
if got := b.Cursor(); got.Line != 1 || got.Col != 2 {
t.Errorf("Cursor() = %+v, want line 1 column 2", got)
}
}
func TestReloadClampsACursorPastTheEndOfTheNewFile(t *testing.T) {
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "one\ntwo\nthree\nfour\n")
b, _ := Open(path)
b.SetCursor(Position{Line: 3, Col: 4})
writeTestFile(t, path, "one\n")
if _, err := b.Reload(); err != nil {
t.Fatalf("Reload() error = %v", err)
}
cursor := b.Cursor()
if cursor.Line >= b.LineCount() {
t.Errorf("Cursor() = %+v, past the end of a %d-line file", cursor, b.LineCount())
}
}
func TestReloadForgetsTheUndoHistory(t *testing.T) {
// Undoing back past a reload would restore text the file no longer has.
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "one\n")
b, _ := Open(path)
b.Insert("x")
if err := b.Save(); err != nil {
t.Fatalf("Save() error = %v", err)
}
writeTestFile(t, path, "reformatted\n")
if _, err := b.Reload(); err != nil {
t.Fatalf("Reload() error = %v", err)
}
b.Undo()
if got := b.Text(); got != "reformatted\n" {
t.Errorf("undo after a reload gave %q", got)
}
}
func TestReloadWithNoPathSaysSo(t *testing.T) {
if _, err := New().Reload(); !errors.Is(err, ErrNoPath) {
t.Errorf("Reload() error = %v, want ErrNoPath", err)
}
}
func TestReloadOfAFileThatHasGoneIsAnError(t *testing.T) {
path := filepath.Join(t.TempDir(), "main.go")
writeTestFile(t, path, "package main\n")
b, _ := Open(path)
if err := os.Remove(path); err != nil {
t.Fatalf("removing the file: %v", err)
}
if _, err := b.Reload(); err == nil {
t.Error("Reload() accepted a file that no longer exists")
}
}
|