spec: error handler

Signed-off-by: Mohammed Al Sahaf <msaa1990@gmail.com>

caddytest/spec/http/error/spec.hurl

@@ -0,0 +1,150 @@
+# Configure Caddy with error directive
+POST http://localhost:2019/load
+Content-Type: text/caddyfile
+```
+{
+	skip_install_trust
+	http_port     9080
+	https_port    9443
+	local_certs
+}
+localhost {
+	error /forbidden* "Access denied" 403
+	respond "OK"
+}
+```
+
+# error directive triggers 403 for matching paths
+GET https://localhost:9443/forbidden/resource
+[Options]
+insecure: true
+HTTP 403
+
+
+# error directive does not trigger for non-matching paths
+GET https://localhost:9443/allowed
+[Options]
+insecure: true
+HTTP 200
+[Asserts]
+body == "OK"
+
+
+# Configure Caddy with error and handle_errors
+POST http://localhost:2019/load
+Content-Type: text/caddyfile
+```
+{
+	skip_install_trust
+	http_port     9080
+	https_port    9443
+	local_certs
+}
+localhost {
+	error /admin* "Forbidden" 403
+	handle_errors {
+		respond "Custom error: {err.status_code} - {err.status_text}"
+	}
+}
+```
+
+# error with handle_errors shows custom error page
+GET https://localhost:9443/admin/panel
+[Options]
+insecure: true
+HTTP 403
+[Asserts]
+body == "Custom error: 403 - Forbidden"
+
+
+# Configure Caddy with conditional error
+POST http://localhost:2019/load
+Content-Type: text/caddyfile
+```
+{
+	skip_install_trust
+	http_port     9080
+	https_port    9443
+	local_certs
+}
+localhost {
+	@admin path /admin*
+	error @admin 404
+	respond "Public content"
+}
+```
+
+# error with named matcher triggers on match
+GET https://localhost:9443/admin/users
+[Options]
+insecure: true
+HTTP 404
+
+
+# error with named matcher doesn't trigger on non-match
+GET https://localhost:9443/public
+[Options]
+insecure: true
+HTTP 200
+[Asserts]
+body == "Public content"
+
+
+# Configure Caddy with error for specific methods
+POST http://localhost:2019/load
+Content-Type: text/caddyfile
+```
+{
+	skip_install_trust
+	http_port     9080
+	https_port    9443
+	local_certs
+}
+localhost {
+	@post method POST
+	error @post "Method not allowed" 405
+	respond "GET OK"
+}
+```
+
+# error blocks POST requests
+POST https://localhost:9443
+[Options]
+insecure: true
+HTTP 405
+
+
+# error allows GET requests
+GET https://localhost:9443
+[Options]
+insecure: true
+HTTP 200
+[Asserts]
+body == "GET OK"
+
+
+# Configure Caddy with dynamic error message
+POST http://localhost:2019/load
+Content-Type: text/caddyfile
+```
+{
+	skip_install_trust
+	http_port     9080
+	https_port    9443
+	local_certs
+}
+localhost {
+	error /error* "Path {path} not found" 404
+	handle_errors {
+		respond "{err.message}"
+	}
+}
+```
+
+# error message can use placeholders
+GET https://localhost:9443/error/test
+[Options]
+insecure: true
+HTTP 404
+[Asserts]
+body == "Path /error/test not found"