Fix eval.toSlice() (#805)

* added tests for use of toSlice() with various HCL attributes

* added bool values handling in to stringification in toSlice()

* added changelog entry

---------

Co-authored-by: Marcel Ludwig <marcel.ludwig@milecrew.com>

CHANGELOG.md

@@ -21,6 +21,7 @@ Unreleased changes are available as `coupergateway/couper:edge` container.
   * [`Server-Timing` header](https://docs.couper.io/configuration/block/settings) only reporting last requests/proxies of [endpoint sequences](https://docs.couper.io/configuration/block/endpoint#endpoint-sequence) ([#751](https://github.com/coupergateway/couper/pull/751))
   * Selecting of appropriate [error handler](https://docs.couper.io/configuration/block/error_handler) in two cases ([#753](https://github.com/coupergateway/couper/pull/753))
   * Storing of digit-starting string object keys in [request context](https://docs.couper.io/configuration/variables#request) and of digit-starting string header field names in [request](https://docs.couper.io/configuration/variables#request) variable ([#799](https://github.com/coupergateway/couper/pull/799))
+  * Use of boolean values for the `headers` attribute or [modifiers](https://docs.couper.io/configuration/modifiers) ([#805](https://github.com/coupergateway/couper/pull/805))
 
 * **Dependencies**
   * build with go 1.21 ([#800](https://github.com/coupergateway/couper/pull/800))

eval/http.go

@@ -535,6 +535,8 @@ func deleteHeader(val cty.Value, headerCtx http.Header) {
 
 func toSlice(val interface{}) []string {
 	switch v := val.(type) {
+	case bool:
+		return []string{strconv.FormatBool(v)}
 	case float64:
 		return []string{strconv.FormatFloat(v, 'f', 0, 64)}
 	case string:

internal/test/test_backend.go

@@ -91,7 +91,7 @@ func registerHTTPHandler(b *Backend) {
 func createAnythingHandler(status int) func(rw http.ResponseWriter, req *http.Request) {
 	return func(rw http.ResponseWriter, req *http.Request) {
 		type anything struct {
-			Args, Query                        url.Values
+			Args, Query, PostForm              url.Values
 			Body                               string
 			Headers                            http.Header
 			Host                               string
@@ -113,6 +113,7 @@ func createAnythingHandler(status int) func(rw http.ResponseWriter, req *http.Re
 			Host:           req.Host,
 			Method:         req.Method,
 			Path:           req.URL.Path,
+			PostForm:       req.PostForm,
 			Query:          req.URL.Query(),
 			RawQuery:       req.URL.RawQuery,
 			RemoteAddr:     req.RemoteAddr,

server/http_endpoints_test.go

@@ -1245,3 +1245,97 @@ func TestEndpointWildcardProxyPathWildcard(t *testing.T) {
 		})
 	}
 }
+
+func Test_toSlice1(t *testing.T) {
+	shutdown, _ := newCouper("testdata/endpoints/22_couper.hcl", test.New(t))
+	defer shutdown()
+
+	expected := map[string][]string{
+		"B":   {"true"},
+		"B2":  {"false"},
+		"Ba":  {"", ""}, // TODO fix: "true", "false"
+		"Ba2": {"", ""}, // TODO fix: "false", "true"
+		"N":   {"1"},
+		"N2":  {"2"},
+		"Na":  {"1", "2"},
+		"Na2": {"3", "4"},
+		"S":   {"str"},
+		"S2":  {"asdf"},
+		"Sa":  {"s1", "s2"},
+		"Sa2": {"s3", "s4"},
+	}
+	helper := test.New(t)
+	res, err := http.PostForm("http://localhost:8080/1", url.Values{})
+	helper.Must(err)
+
+	if res.StatusCode != http.StatusOK {
+		t.Errorf("Unexpected status: want: 200, got %d", res.StatusCode)
+	}
+
+	b, err := io.ReadAll(res.Body)
+	helper.Must(res.Body.Close())
+	helper.Must(err)
+
+	type result struct {
+		PostForm, Query, Headers map[string][]string
+	}
+	r := result{}
+	helper.Must(json.Unmarshal(b, &r))
+	if diff := cmp.Diff(r.Query, expected); diff != "" {
+		t.Error(diff)
+	}
+	if diff := cmp.Diff(r.PostForm, expected); diff != "" {
+		t.Error(diff)
+	}
+	for k, v := range expected {
+		if diff := cmp.Diff(r.Headers[k], v); diff != "" {
+			t.Error(diff)
+		}
+	}
+	for k, v := range expected {
+		if diff := cmp.Diff(res.Header[k], v); diff != "" {
+			t.Error(diff)
+		}
+	}
+}
+
+func Test_toSlice2(t *testing.T) {
+	shutdown, _ := newCouper("testdata/endpoints/22_couper.hcl", test.New(t))
+	defer shutdown()
+
+	expected := map[string][]string{
+		"B":  {"true"},
+		"Ba": {"", ""}, // TODO fix: "true", "false"
+		"N":  {"1"},
+		"Na": {"1", "2"},
+		"S":  {"str"},
+		"Sa": {"s1", "s2"},
+	}
+	helper := test.New(t)
+	res, err := http.Get("http://localhost:8080/2")
+	helper.Must(err)
+
+	if res.StatusCode != http.StatusOK {
+		t.Errorf("Unexpected status: want: 200, got %d", res.StatusCode)
+	}
+
+	b, err := io.ReadAll(res.Body)
+	helper.Must(res.Body.Close())
+	helper.Must(err)
+
+	type result struct {
+		Headers map[string][]string
+	}
+	r := result{}
+	helper.Must(json.Unmarshal(b, &r))
+	for k, v := range expected {
+		if diff := cmp.Diff(r.Headers[k], v); diff != "" {
+			t.Error(diff)
+		}
+	}
+	for k, v := range expected {
+		if diff := cmp.Diff(res.Header[k], v); diff != "" {
+			t.Error(diff)
+		}
+	}
+}

server/http_integration_test.go

@@ -4250,7 +4250,7 @@ func TestFunctions(t *testing.T) {
 			"X-Default-9":  "",
 			"X-Default-10": "",
 			"X-Default-11": "0",
-			"X-Default-12": "",
+			"X-Default-12": "false",
 			"X-Default-13": `{"a":1}`,
 			"X-Default-14": `{"a":1}`,
 			"X-Default-15": `[1,2]`,

server/testdata/endpoints/22_couper.hcl

@@ -0,0 +1,106 @@
+server "cl" {
+  api {
+    endpoint "/1" {
+      proxy {
+        backend = "be"
+      }
+      set_query_params = {
+        B = true
+        N = 1
+        S = "str"
+        Ba = [true, false]
+        Na = [1, 2]
+        Sa = ["s1", "s2"]
+      }
+      add_query_params = {
+        B2 = false
+        N2 = 2
+        S2 = "asdf"
+        Ba2 = [false, true]
+        Na2 = [3, 4]
+        Sa2 = ["s3", "s4"]
+      }
+      set_form_params = {
+        B = true
+        N = 1
+        S = "str"
+        Ba = [true, false]
+        Na = [1, 2]
+        Sa = ["s1", "s2"]
+      }
+      add_form_params = {
+        B2 = false
+        N2 = 2
+        S2 = "asdf"
+        Ba2 = [false, true]
+        Na2 = [3, 4]
+        Sa2 = ["s3", "s4"]
+      }
+      set_request_headers = {
+        B = true
+        N = 1
+        S = "str"
+        Ba = [true, false]
+        Na = [1, 2]
+        Sa = ["s1", "s2"]
+      }
+      add_request_headers = {
+        B2 = false
+        N2 = 2
+        S2 = "asdf"
+        Ba2 = [false, true]
+        Na2 = [3, 4]
+        Sa2 = ["s3", "s4"]
+      }
+      set_response_headers = {
+        B = true
+        N = 1
+        S = "str"
+        Ba = [true, false]
+        Na = [1, 2]
+        Sa = ["s1", "s2"]
+      }
+      add_response_headers = {
+        B2 = false
+        N2 = 2
+        S2 = "asdf"
+        Ba2 = [false, true]
+        Na2 = [3, 4]
+        Sa2 = ["s3", "s4"]
+      }
+    }
+
+    endpoint "/2" {
+      request {
+        url = "/anything"
+        backend = "be"
+        headers = {
+          B = true
+          N = 1
+          S = "str"
+          Ba = [true, false]
+          Na = [1, 2]
+          Sa = ["s1", "s2"]
+        }
+      }
+      response {
+        headers = {
+          B = true
+          N = 1
+          S = "str"
+          Ba = [true, false]
+          Na = [1, 2]
+          Sa = ["s1", "s2"]
+        }
+        body = backend_responses.default.body
+      }
+    }
+  }
+}
+
+definitions {
+  backend "be" {
+    origin = "${env.COUPER_TEST_BACKEND_ADDR}"
+    path = "/anything"
+  }
+}