gui: syntax colours, a file preview, and a settings window

1 files changed, 98 insertions, 0 deletions

diff --git a/gui/internal/model/preview_test.go b/gui/internal/model/preview_test.go
new file mode 100644
index 0000000..8c19922
--- /dev/null
+++ b/gui/internal/model/preview_test.go
@@ -0,0 +1,98 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package model
+
+import (
+	"context"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+)
+
+// TestPreviewKinds: a text file comes back as text, a picture as a picture,
+// and something krino cannot show says so instead of guessing.
+func TestPreviewKinds(t *testing.T) {
+	dir := t.TempDir()
+	write := func(name string, body []byte) string {
+		p := filepath.Join(dir, name)
+		if err := os.WriteFile(p, body, 0o644); err != nil {
+			t.Fatal(err)
+		}
+		return p
+	}
+	text := write("notes.txt", []byte("first line\nsecond line\n"))
+	png := write("a.png", []byte("\x89PNG\r\n\x1a\nnot really, but the name is what counts here"))
+	binary := write("a.bin", []byte{0, 1, 2, 3, 0})
+	tmp := t.TempDir()
+
+	if p := MakePreview(context.Background(), text, tmp); p.Kind != PreviewText ||
+		!strings.Contains(p.Text, "second line") {
+		t.Errorf("text preview = %+v", p)
+	}
+	if p := MakePreview(context.Background(), png, tmp); p.Kind != PreviewImage || p.Image != png {
+		t.Errorf("image preview = %+v", p)
+	}
+	if p := MakePreview(context.Background(), binary, tmp); p.Kind != PreviewNone ||
+		!strings.Contains(p.Note, "no preview") {
+		t.Errorf("binary preview = %+v", p)
+	}
+	if p := MakePreview(context.Background(), filepath.Join(dir, "gone.txt"), tmp); p.Kind != PreviewNone {
+		t.Errorf("a missing file = %+v", p)
+	}
+	if p := MakePreview(context.Background(), dir, tmp); p.Kind != PreviewNone {
+		t.Errorf("a directory = %+v", p)
+	}
+}
+
+// TestPreviewReadsOnly: looking at a file changes nothing about it, and
+// nothing is left beside it.
+func TestPreviewReadsOnly(t *testing.T) {
+	dir := t.TempDir()
+	p := filepath.Join(dir, "notes.txt")
+	body := []byte("one\ntwo\n")
+	if err := os.WriteFile(p, body, 0o644); err != nil {
+		t.Fatal(err)
+	}
+	before, err := os.Stat(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	MakePreview(context.Background(), p, t.TempDir())
+	after, err := os.Stat(p)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if !before.ModTime().Equal(after.ModTime()) || before.Size() != after.Size() {
+		t.Error("the file changed")
+	}
+	if entries, _ := os.ReadDir(dir); len(entries) != 1 {
+		t.Errorf("the directory holds %d files, want the one", len(entries))
+	}
+	if on, _ := os.ReadFile(p); string(on) != string(body) {
+		t.Error("the contents changed")
+	}
+}
+
+// TestPreviewShowsOnlyTheHead: a long file is cut, and says it was.
+func TestPreviewShowsOnlyTheHead(t *testing.T) {
+	dir := t.TempDir()
+	p := filepath.Join(dir, "long.txt")
+	var b strings.Builder
+	for i := 0; i < previewLines*2; i++ {
+		b.WriteString("line\n")
+	}
+	if err := os.WriteFile(p, []byte(b.String()), 0o644); err != nil {
+		t.Fatal(err)
+	}
+	pv := MakePreview(context.Background(), p, t.TempDir())
+	if pv.Kind != PreviewText {
+		t.Fatalf("preview = %+v", pv)
+	}
+	if n := strings.Count(pv.Text, "\n"); n > previewLines+1 {
+		t.Errorf("%d lines shown, want at most %d", n, previewLines)
+	}
+	if !strings.HasSuffix(pv.Text, "...") {
+		t.Error("a cut file does not say it was cut")
+	}
+}