moving editor

Author: grantnelson-wf

playground/go.mod

@@ -3,6 +3,7 @@ module github.com/gopherjs/gopherjs.github.io/playground
 go 1.19
 
 require (
+	github.com/google/go-cmp v0.5.8
 	github.com/gopherjs/gopherjs v1.19.0-beta2.0.20251008200541-113c92b42b18
 	golang.org/x/tools v0.16.0
 	honnef.co/go/js/xhr v0.0.0-20150307031022-00e3346113ae

playground/go.sum

@@ -0,0 +1,121 @@
+package editor
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/google/go-cmp/cmp"
+)
+
+func Test_Editor_ProcessKeyDown(t *testing.T) {
+	tests := []struct {
+		name           string
+		code           string
+		key            string
+		shift          bool
+		ctrl           bool
+		selectionStart int
+		selectionEnd   int
+
+		wantCode           string
+		wantSelectionStart int
+		wantSelectionEnd   int
+		wantPrefentDefault bool
+		wantSaveCalls      int
+		wantEscapeCalls    int
+	}{
+		{
+			name: "Tab key with caret",
+			code: lines(
+				`package main`,
+				``,
+				`func main() {`,
+				`}`),
+			key:            "Tab",
+			selectionStart: 20,
+			selectionEnd:   20,
+
+			wantCode: lines(
+				`package main`,
+				``,
+				`func main() {`,
+				`	`,
+				`}`),
+			wantSelectionStart: 21,
+			wantSelectionEnd:   21,
+			wantPrefentDefault: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			gotCode := tt.code
+			cb := &fakeCodeBox{
+				initCode:           tt.code,
+				initSelectionStart: tt.selectionStart,
+				initSelectionEnd:   tt.selectionEnd,
+			}
+			gotPreventDefault := ProcessKeyDown(cb, tt.key, tt.shift, tt.ctrl)
+			check(t, "code", gotCode, tt.wantCode)
+			check(t, "selectedStart", cb.gotSelectionStart, tt.wantSelectionStart)
+			check(t, "selectedEnd", cb.gotSelectionEnd, tt.wantSelectionEnd)
+			check(t, "preventDefault", gotPreventDefault, tt.wantPrefentDefault)
+			check(t, "saveCalls", cb.getSaveCalls, tt.wantSaveCalls)
+			check(t, "escapeCalls", cb.gotEscapeCalls, tt.wantEscapeCalls)
+		})
+	}
+}
+
+type fakeCodeBox struct {
+	initCode           string
+	initSelectionStart int
+	initSelectionEnd   int
+
+	gotCode           string
+	gotSelectionStart int
+	gotSelectionEnd   int
+	getSaveCalls      int
+	gotEscapeCalls    int
+}
+
+var _ CodeBoxWrapper = (*fakeCodeBox)(nil)
+
+func (cb *fakeCodeBox) Code() string        { return cb.initCode }
+func (cb *fakeCodeBox) SetCode(code string) { cb.gotCode = code }
+func (cb *fakeCodeBox) EmitSave()           { cb.getSaveCalls++ }
+func (cb *fakeCodeBox) EmitEscape()         { cb.gotEscapeCalls++ }
+
+func (cb *fakeCodeBox) GetSelection() (int, int) {
+	return cb.initSelectionStart, cb.initSelectionEnd
+}
+
+func (cb *fakeCodeBox) SetSelection(start, end int, _ string) {
+	cb.gotSelectionStart = start
+	cb.gotSelectionEnd = end
+}
+
+func lines(lines ...string) string {
+	return strings.Join(lines, "\n")
+}
+
+func check[T comparable](t *testing.T, name string, got, want T) {
+	t.Helper()
+
+	switch any(want).(type) {
+	case string:
+		if diff := cmp.Diff(want, got); len(diff) > 0 {
+			t.Errorf("%s was not as expected:\n"+
+				"  want: %q\n"+
+				"  got:  %q\n"+
+				"  diff:\n%s", name, any(want).(string), any(got).(string),
+				strings.ReplaceAll(diff, "\n", "\n    "))
+		}
+		return
+	}
+
+	if got != want {
+		t.Errorf("%s was not as expected:\n"+
+			"  want: %v\n"+
+			"  got:  %v", name, want, got)
+	}
+}