feat(captcha): deterministic HTML detection for known providers

internal/captcha/detect_test.go

@@ -0,0 +1,29 @@
+package captcha
+
+import "testing"
+
+func TestDetectHTML(t *testing.T) {
+	tests := []struct {
+		name         string
+		html         string
+		wantType     string
+		wantSolvable bool
+	}{
+		{"recaptcha v2", `<div class="g-recaptcha" data-sitekey="6Lc_abc"></div>`, "recaptcha_v2", true},
+		{"recaptcha v3", `<script src="https://www.google.com/recaptcha/api.js?render=6Lc_v3key"></script>`, "recaptcha_v3", false},
+		{"hcaptcha", `<div class="h-captcha" data-sitekey="hk_123"></div>`, "hcaptcha", true},
+		{"turnstile", `<div class="cf-turnstile" data-sitekey="0x4AAA"></div>`, "turnstile", false},
+		{"funcaptcha", `<div id="arkose" data-pkey="ABC"></div>`, "funcaptcha", true},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			got := DetectHTML(tc.html)
+			if len(got) == 0 {
+				t.Fatalf("no detection")
+			}
+			if got[0].Type != tc.wantType || got[0].LLMSolvable != tc.wantSolvable {
+				t.Fatalf("got %+v", got[0])
+			}
+		})
+	}
+}