[bugfix] Add sentinel error for non-err failure after retries and handle appropriately

go.mod

@@ -1,11 +1,13 @@
 module github.com/fako1024/httpc
 
-go 1.20
+go 1.22.5
+
+toolchain go1.24.0
 
 require (
-	github.com/getkin/kin-openapi v0.128.0
+	github.com/getkin/kin-openapi v0.129.0
 	github.com/json-iterator/go v1.1.12
-	golang.org/x/net v0.33.0
+	golang.org/x/net v0.35.0
 	gopkg.in/h2non/gock.v1 v1.1.2
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -14,11 +16,12 @@ require (
 	github.com/go-openapi/jsonpointer v0.21.0 // indirect
 	github.com/go-openapi/swag v0.23.0 // indirect
 	github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 // indirect
-	github.com/invopop/yaml v0.3.1 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/mailru/easyjson v0.9.0 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 // indirect
+	github.com/oasdiff/yaml v0.0.0-20241214135536-5f7845c759c8 // indirect
+	github.com/oasdiff/yaml3 v0.0.0-20241214160948-977117996672 // indirect
 	github.com/perimeterx/marshmallow v1.1.5 // indirect
 )

go.sum

@@ -1,27 +1,27 @@
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
 github.com/davecgh/go-spew v1.1.1 h1:vj9j/u1bqnvCEfJOwUhtlOARqs3+rkHYY13jYWTU97c=
 github.com/davecgh/go-spew v1.1.1/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
-github.com/getkin/kin-openapi v0.128.0 h1:jqq3D9vC9pPq1dGcOCv7yOp1DaEe7c/T1vzcLbITSp4=
-github.com/getkin/kin-openapi v0.128.0/go.mod h1:OZrfXzUfGrNbsKj+xmFBx6E5c6yH3At/tAKSc2UszXM=
+github.com/getkin/kin-openapi v0.129.0 h1:QGYTNcmyP5X0AtFQ2Dkou9DGBJsUETeLH9rFrJXZh30=
+github.com/getkin/kin-openapi v0.129.0/go.mod h1:gmWI+b/J45xqpyK5wJmRRZse5wefA5H0RDMK46kLUtI=
 github.com/go-openapi/jsonpointer v0.21.0 h1:YgdVicSA9vH5RiHs9TZW5oyafXZFc6+2Vc1rr/O9oNQ=
 github.com/go-openapi/jsonpointer v0.21.0/go.mod h1:IUyH9l/+uyhIYQ/PXVA41Rexl+kOkAPDdXEYns6fzUY=
 github.com/go-openapi/swag v0.23.0 h1:vsEVJDUo2hPJ2tu0/Xc+4noaxyEffXNIs3cOULZ+GrE=
 github.com/go-openapi/swag v0.23.0/go.mod h1:esZ8ITTYEsH1V2trKHjAN8Ai7xHb8RV+YSZ577vPjgQ=
 github.com/go-test/deep v1.0.8 h1:TDsG77qcSprGbC6vTN8OuXp5g+J+b5Pcguhf7Zt61VM=
+github.com/go-test/deep v1.0.8/go.mod h1:5C2ZWiW0ErCdrYzpqxLbTX7MG14M9iiw8DgHncVwcsE=
 github.com/google/gofuzz v1.0.0/go.mod h1:dBl0BpW6vV/+mYPU4Po3pmUjxk6FQPldtuIdl/M65Eg=
 github.com/gorilla/mux v1.8.0 h1:i40aqfkR1h2SlN9hojwV5ZA91wcXFOvkdNIeFDP5koI=
+github.com/gorilla/mux v1.8.0/go.mod h1:DVbg23sWSpFRCP0SfiEN6jmj59UnW/n46BH5rLB71So=
 github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542 h1:2VTzZjLZBgl62/EtslCrtky5vbi9dd7HrQPQIx6wqiw=
 github.com/h2non/parth v0.0.0-20190131123155-b4df798d6542/go.mod h1:Ow0tF8D4Kplbc8s8sSb3V2oUCygFHVp8gC3Dn6U4MNI=
-github.com/invopop/yaml v0.3.1 h1:f0+ZpmhfBSS4MhG+4HYseMdJhoeeopbSKbq5Rpeelso=
-github.com/invopop/yaml v0.3.1/go.mod h1:PMOp3nn4/12yEZUFfmOuNHJsZToEEOwoWsT+D81KkeA=
 github.com/josharian/intern v1.0.0 h1:vlS4z54oSdjm0bgjRigI+G1HpF+tI+9rE5LLzOg8HmY=
 github.com/josharian/intern v1.0.0/go.mod h1:5DoeVV0s6jJacbCEi61lwdGj/aVlrQvzHFFd8Hwg//Y=
 github.com/json-iterator/go v1.1.12 h1:PV8peI4a0ysnczrg+LtxykD8LfKY9ML6u2jnxaEnrnM=
 github.com/json-iterator/go v1.1.12/go.mod h1:e30LSqwooZae/UwlEbR2852Gd8hjQvJoHmT4TnhNGBo=
 github.com/kr/pretty v0.3.1 h1:flRD4NNwYAUpkphVc1HcthR4KEIFJ65n8Mw5qdRn3LE=
+github.com/kr/pretty v0.3.1/go.mod h1:hoEshYVHaxMs3cyo3Yncou5ZscifuDolrwPKZanG3xk=
 github.com/kr/text v0.2.0 h1:5Nx0Ya0ZqY2ygV366QzturHI13Jq95ApcVaJBhpS+AY=
-github.com/mailru/easyjson v0.7.7 h1:UGYAvKxe3sBsEDzO8ZeWOSlIQfWFlxbzLZe7hwFURr0=
-github.com/mailru/easyjson v0.7.7/go.mod h1:xzfreul335JAWq5oZzymOObrkdz5UnU4kGfJJLY9Nlc=
+github.com/kr/text v0.2.0/go.mod h1:eLer722TekiGuMkidMxC/pM04lWEeraHUUmBw8l2grE=
 github.com/mailru/easyjson v0.9.0 h1:PrnmzHw7262yW8sTBwxi1PdJA3Iw/EKBa8psRf7d9a4=
 github.com/mailru/easyjson v0.9.0/go.mod h1:1+xMtQp2MRNVL/V1bOzuP3aP8VNwRW55fQUto+XFtTU=
 github.com/modern-go/concurrent v0.0.0-20180228061459-e0a39a4cb421/go.mod h1:6dJC0mAP4ikYIbvyc7fijjWJddQyLn8Ig3JB5CqoB9Q=
@@ -33,21 +33,27 @@ github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826 h1:RWengNIwukTxcDr9
 github.com/mohae/deepcopy v0.0.0-20170929034955-c48cc78d4826/go.mod h1:TaXosZuwdSHYgviHp1DAtfrULt5eUgsSMsZf+YrPgl8=
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32 h1:W6apQkHrMkS0Muv8G/TipAy/FJl/rCYT0+EuS8+Z0z4=
 github.com/nbio/st v0.0.0-20140626010706-e9e8d9816f32/go.mod h1:9wM+0iRr9ahx58uYLpLIr5fm8diHn0JbqRycJi6w0Ms=
+github.com/oasdiff/yaml v0.0.0-20241214135536-5f7845c759c8 h1:9djga8U4+/TQzv5iMlZHZ/qbGQB9V2nlnk2bmiG+uBs=
+github.com/oasdiff/yaml v0.0.0-20241214135536-5f7845c759c8/go.mod h1:7tFDb+Y51LcDpn26GccuUgQXUk6t0CXZsivKjyimYX8=
+github.com/oasdiff/yaml3 v0.0.0-20241214160948-977117996672 h1:+273wgr7to5QhwOOBE5LwjdNDFAI+8cbJVfB0Zj75aI=
+github.com/oasdiff/yaml3 v0.0.0-20241214160948-977117996672/go.mod h1:y5+oSEHCPT/DGrS++Wc/479ERge0zTFxaF8PbGKcg2o=
 github.com/perimeterx/marshmallow v1.1.5 h1:a2LALqQ1BlHM8PZblsDdidgv1mWi1DgC2UmX50IvK2s=
 github.com/perimeterx/marshmallow v1.1.5/go.mod h1:dsXbUu8CRzfYP5a87xpp0xq9S3u0Vchtcl8we9tYaXw=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/rogpeppe/go-internal v1.12.0 h1:exVL4IDcn6na9z1rAb56Vxr+CgyK3nn3O+epU5NdKM8=
+github.com/rogpeppe/go-internal v1.12.0/go.mod h1:E+RYuTGaKKdloAfM02xzb0FW3Paa99yedzYV+kq4uf4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 github.com/stretchr/testify v1.9.0 h1:HtqpIVDClZ4nwg75+f6Lvsy/wHu+3BoSGCbBAcpTsTg=
+github.com/stretchr/testify v1.9.0/go.mod h1:r2ic/lqez/lEtzL7wO/rwa5dbSLXVDPFyf8C91i36aY=
 github.com/ugorji/go/codec v1.2.7 h1:YPXUKf7fYbp/y8xloBqZOw2qaVggbfwMlI8WM3wZUJ0=
-golang.org/x/net v0.30.0 h1:AcW1SDZMkb8IpzCdQUaIq2sP4sZ4zw+55h6ynffypl4=
-golang.org/x/net v0.30.0/go.mod h1:2wGyMJ5iFasEhkwi13ChkO/t1ECNC4X4eBKkVFyYFlU=
-golang.org/x/net v0.33.0 h1:74SYHlV8BIgHIFC/LrYkOGIwL19eTYXQ5wc6TBuO36I=
-golang.org/x/net v0.33.0/go.mod h1:HXLR5J+9DxmrqMwG9qjGCxZ+zKXxBru04zlTvWlWuN4=
+github.com/ugorji/go/codec v1.2.7/go.mod h1:WGN1fab3R1fzQlVQTkfxVtIBhWDRqOviHU95kRgeqEY=
+golang.org/x/net v0.35.0 h1:T5GQRQb2y08kTAByq9L4/bz8cipCdA8FbRTXewonqY8=
+golang.org/x/net v0.35.0/go.mod h1:EglIi67kWsHKlRzzVMUD93VMSWGFOMSZgxFjparz1Qk=
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c h1:Hei/4ADfdWqJk1ZMxUNpqntNwaWcugrBjAiHlqqRiVk=
+gopkg.in/check.v1 v1.0.0-20201130134442-10cb98267c6c/go.mod h1:JHkPIbrfpd72SG/EVd6muEfDQjcINNoR0C8j2r3qZ4Q=
 gopkg.in/h2non/gock.v1 v1.1.2 h1:jBbHXgGBK/AoPVfJh5x4r/WxIrElvbLel8TCZkkZJoY=
 gopkg.in/h2non/gock.v1 v1.1.2/go.mod h1:n7UGz/ckNChHiK05rDoiC4MYSunEC/lyaUm2WWaDva0=
 gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=

httpc.go

@@ -23,15 +23,21 @@ const (
 	contentTypeHeaderValRFC9457 = "application/problem+json"
 )
 
-var defaultacceptedResponseCodes = []int{
-	http.StatusOK,
-	http.StatusCreated,
-	http.StatusAccepted,
-}
+var (
+	// ErrErrRetryLimit denotes that the maximum number of retries has been reached,
+	// e.g. for a non-standard RetryErrFn (that may trigger on a non-err status)
+	ErrRetryLimit = errors.New("maximum number of request retries reached")
+
+	defaultacceptedResponseCodes = []int{
+		http.StatusOK,
+		http.StatusCreated,
+		http.StatusAccepted,
+	}
 
-var defaultRetryErrFn = func(resp *http.Response, err error) bool {
-	return err != nil
-}
+	defaultRetryErrFn = func(resp *http.Response, err error) bool {
+		return err != nil
+	}
+)
 
 // Params is an alias for a map of string key / value pairs
 type Params = map[string]string
@@ -479,8 +485,13 @@ func (r *Request) RunWithContext(ctx context.Context) error {
 		}
 		resp, err = r.client.Do(req)
 	}
+
+	// If the cause was an actual error, return it - otherwise return sentinel error
 	if retryErrFn(resp, err) {
-		return err
+		if err != nil {
+			return err
+		}
+		return ErrRetryLimit
 	}
 
 	defer func() {

httpc_issues_test.go

@@ -0,0 +1,45 @@
+package httpc
+
+import (
+	"errors"
+	"net/http"
+	"testing"
+	"time"
+
+	"gopkg.in/h2non/gock.v1"
+)
+
+// Too many retries leads to... success
+// https://github.com/fako1024/httpc/issues/43
+func TestIssue43FailedRetriesLeadToSuccedd(t *testing.T) {
+	uri := joinURI(httpsEndpoint, "issue_43")
+
+	// Set up a mock matcher
+	g := gock.New(uri)
+	g.Persist().
+		Get("/").
+		Reply(http.StatusInternalServerError)
+
+	req := New(http.MethodGet, uri).
+		RetryBackOffErrFn(func(resp *http.Response, err error) bool {
+			if resp == nil || err != nil {
+				return true
+			}
+			if resp.StatusCode >= 200 && resp.StatusCode < 300 {
+				return false
+			}
+			return true
+		}).
+		RetryBackOff(Intervals{time.Millisecond, time.Millisecond, time.Millisecond})
+
+	gock.InterceptClient(req.client)
+	defer gock.RestoreClient(req.client)
+
+	err := req.Run()
+	if err == nil {
+		t.Fatal("expected error, got none")
+	}
+	if !errors.Is(err, ErrRetryLimit) {
+		t.Fatalf("unexpected error, want %s, have %s", ErrRetryLimit, err)
+	}
+}

httpc_test.go

@@ -1420,7 +1420,7 @@ func runDummyTLSServer() {
 		panic(err)
 	}
 	if !caCertPool.AppendCertsFromPEM([]byte(testCACert)) {
-		panic(err)
+		panic("failed to append dummy TLS server certificates")
 	}
 
 	config := &tls.Config{