Removing Closer from build_policies

By instruction of Martin, I removed Closer from build_policies and added
warning comments to the code instead.

pkg/lib/api/build_policies.go

@@ -13,7 +13,7 @@ import (
 	"github.com/programmfabrik/apitest/pkg/lib/util"
 )
 
-func buildMultipart(request Request) (additionalHeaders map[string]string, body io.Reader, bodyCloser io.Closer, err error) {
+func buildMultipart(request Request) (additionalHeaders map[string]string, body io.Reader, err error) {
 	additionalHeaders = make(map[string]string, 0)
 
 	var buf = bytes.NewBuffer([]byte{})
@@ -24,7 +24,7 @@ func buildMultipart(request Request) (additionalHeaders map[string]string, body
 	if ok {
 		f, ok := val.(util.JsonString)
 		if !ok {
-			return additionalHeaders, body, nil, fmt.Errorf("file:filename should be a string")
+			return nil, nil, fmt.Errorf("file:filename should be a string")
 		}
 		replaceFilename = &f
 	}
@@ -70,7 +70,7 @@ func buildMultipart(request Request) (additionalHeaders map[string]string, body
 	for key, val := range request.Body.(map[string]any) {
 		err = createPart(key, val)
 		if err != nil {
-			return additionalHeaders, body, bodyCloser, err
+			return nil, nil, err
 		}
 	}
 
@@ -80,7 +80,7 @@ func buildMultipart(request Request) (additionalHeaders map[string]string, body
 	return
 }
 
-func buildUrlencoded(request Request) (additionalHeaders map[string]string, body io.Reader, bodyCloser io.Closer, err error) {
+func buildUrlencoded(request Request) (additionalHeaders map[string]string, body io.Reader, err error) {
 	additionalHeaders = make(map[string]string, 0)
 	additionalHeaders["Content-Type"] = "application/x-www-form-urlencoded"
 	formParams := url.Values{}
@@ -95,11 +95,11 @@ func buildUrlencoded(request Request) (additionalHeaders map[string]string, body
 		}
 	}
 	body = strings.NewReader(formParams.Encode())
-	return additionalHeaders, body, nil, nil
+	return additionalHeaders, body, nil
 
 }
 
-func buildRegular(request Request) (additionalHeaders map[string]string, body io.Reader, bodyCloser io.Closer, err error) {
+func buildRegular(request Request) (additionalHeaders map[string]string, body io.Reader, err error) {
 	additionalHeaders = make(map[string]string, 0)
 	additionalHeaders["Content-Type"] = "application/json"
 
@@ -108,18 +108,20 @@ func buildRegular(request Request) (additionalHeaders map[string]string, body io
 	} else {
 		bodyBytes, err := json.Marshal(request.Body)
 		if err != nil {
-			return additionalHeaders, body, nil, fmt.Errorf("error marshaling request body: %s", err)
+			return nil, nil, fmt.Errorf("error marshaling request body: %s", err)
 		}
 		body = bytes.NewBuffer(bodyBytes)
 	}
-	return additionalHeaders, body, nil, nil
+	return additionalHeaders, body, nil
 }
 
-func buildFile(req Request) (map[string]string, io.Reader, io.Closer, error) {
+// buildFile opens a file for use with buildPolicy.
+// WARNING: This returns a file handle that must be closed!
+func buildFile(req Request) (map[string]string, io.Reader, error) {
 	headers := map[string]string{}
 
 	if req.BodyFile == "" {
-		return nil, nil, nil, errors.New(`Request.buildFile: Missing "body_file"`)
+		return nil, nil, errors.New(`Request.buildFile: Missing "body_file"`)
 	}
 
 	path := req.BodyFile
@@ -130,7 +132,7 @@ func buildFile(req Request) (map[string]string, io.Reader, io.Closer, error) {
 
 	file, err := util.OpenFileOrUrl(path, req.ManifestDir)
 	if err != nil {
-		return nil, nil, nil, err
+		return nil, nil, err
 	}
-	return headers, file, file, err
+	return headers, file, err
 }

pkg/lib/api/build_policies_test.go

@@ -26,7 +26,6 @@ func TestBuildMultipart(t *testing.T) {
 		ManifestDir: "test/",
 		BodyType:    "multipart",
 	}
-	defer testRequest.Close()
 
 	httpRequest, err := testRequest.buildHttpRequest()
 	go_test_utils.ExpectNoError(t, err, "error building multipart request")
@@ -50,7 +49,7 @@ func TestBuildMultipart_ErrPathSpec(t *testing.T) {
 		ManifestDir: "test/path/",
 	}
 
-	_, _, _, err := buildMultipart(testRequest)
+	_, _, err := buildMultipart(testRequest)
 	if err == nil {
 		t.Fatal("expected error")
 	}
@@ -67,7 +66,7 @@ func TestBuildMultipart_ErrPathSpecNoString(t *testing.T) {
 		ManifestDir: "test/path/",
 	}
 
-	_, _, _, err := buildMultipart(testRequest)
+	_, _, err := buildMultipart(testRequest)
 	if err == nil {
 		t.Fatal("expected error")
 	}
@@ -84,7 +83,7 @@ func TestBuildMultipart_FileDoesNotExist(t *testing.T) {
 		ManifestDir: "test/path/",
 	}
 
-	_, _, _, err := buildMultipart(testRequest)
+	_, _, err := buildMultipart(testRequest)
 	if err == nil {
 		t.Fatal("expected error")
 	}

pkg/lib/api/request.go

@@ -57,8 +57,7 @@ type Request struct {
 	BodyFile             string                    `yaml:"body_file" json:"body_file"`
 	Body                 any                       `yaml:"body" json:"body"`
 
-	buildPolicy func(Request) (additionalHeaders map[string]string, body io.Reader, bodyCloser io.Closer, err error)
-	bodyCloser  io.Closer
+	buildPolicy func(Request) (additionalHeaders map[string]string, body io.Reader, err error)
 	ManifestDir string
 	DataStore   *datastore.Datastore
 }
@@ -89,16 +88,14 @@ func (request Request) buildHttpRequest() (req *http.Request, err error) {
 		return nil, errors.Wrapf(err, "Unable to buildHttpRequest with URL %q", requestUrl)
 	}
 
-	if request.bodyCloser != nil {
-		// in case bodyCloser is already set, close the old body first
-		request.bodyCloser.Close()
-	}
-
-	additionalHeaders, body, bodyCloser, err := request.buildPolicy(request)
+	// Note that buildPolicy may return a file handle that needs to be
+	// closed. According to standard library documentation, the NewRequest
+	// call below will take into account if body also happens to implement
+	// io.Closer.
+	additionalHeaders, body, err := request.buildPolicy(request)
 	if err != nil {
 		return req, fmt.Errorf("error executing buildpolicy: %s", err)
 	}
-	request.bodyCloser = bodyCloser
 
 	req, err = http.NewRequest(request.Method, requestUrl, body)
 	if err != nil {
@@ -273,14 +270,6 @@ func (request Request) buildHttpRequest() (req *http.Request, err error) {
 	return req, nil
 }
 
-func (request Request) Close() error {
-	if request.bodyCloser != nil {
-		return request.bodyCloser.Close()
-	}
-
-	return nil
-}
-
 func (request Request) ToString(curl bool) (res string) {
 	httpRequest, err := request.buildHttpRequest()
 	if err != nil {

pkg/lib/api/request_test.go

@@ -21,12 +21,11 @@ func TestRequestBuildHttp(t *testing.T) {
 		},
 		ServerURL: "serverUrl",
 	}
-	defer request.Close()
-	request.buildPolicy = func(request Request) (ah map[string]string, b io.Reader, c io.Closer, err error) {
+	request.buildPolicy = func(request Request) (ah map[string]string, b io.Reader, err error) {
 		ah = make(map[string]string)
 		ah["mock-header"] = "application/mock"
 		b = strings.NewReader("mock_body")
-		return ah, b, c, nil
+		return ah, b, nil
 	}
 	httpRequest, err := request.buildHttpRequest()
 	go_test_utils.ExpectNoError(t, err, fmt.Sprintf("error building http-request: %s", err))
@@ -88,7 +87,6 @@ func TestRequestBuildHttpWithCookie(t *testing.T) {
 		Method:   "GET",
 		Cookies:  reqCookies,
 	}
-	defer request.Close()
 	request.buildPolicy = buildRegular
 	ds := datastore.NewStore(false)
 	for key, val := range storeCookies {