package classes

import "testing"

// TestSetImageAlt pins the alt rewrite: only the matching img tag is
// rewritten from its token, the alt is escaped, a missing alt is added and
// every other byte is kept (T-33-04).
func TestSetImageAlt(t *testing.T) {
	const doc = `<p class="a">x &amp; y</p><img src="https://cdn.example.test/a.jpg?x=1&amp;y=2"><img src="b.jpg" alt="old"/>`
	out, n, old := SetImageAlt(doc, "https://cdn.example.test/a.jpg?x=1&y=2", `Lion's "mane" <b>`)
	want := `<p class="a">x &amp; y</p><img src="https://cdn.example.test/a.jpg?x=1&amp;y=2" alt="Lion&#39;s &#34;mane&#34; &lt;b&gt;"><img src="b.jpg" alt="old"/>`
	if out != want || n != 1 || old != nil {
		t.Fatalf("SetImageAlt = %q, %d, %v; want %q, 1, nil", out, n, old, want)
	}
	out, n, old = SetImageAlt(doc, "b.jpg", "")
	if out != `<p class="a">x &amp; y</p><img src="https://cdn.example.test/a.jpg?x=1&amp;y=2"><img src="b.jpg" alt=""/>` || n != 1 || old == nil || *old != "old" {
		t.Fatalf("decorative = %q, %d, %v", out, n, old)
	}
	if out, n, _ := SetImageAlt(doc, "missing.jpg", "x"); out != doc || n != 0 {
		t.Fatalf("missing = %q, %d", out, n)
	}
}