From b863648faaa3d487d3cbef0e61b5c348376fa410 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Fri, 12 Apr 2024 10:24:19 +0300
Subject: [PATCH 01/14] fix: propagate body stream error to close function
 (#1743)

---
 client.go |  4 ++--
 http.go   | 40 ++++++++++++++++++++++++----------------
 2 files changed, 26 insertions(+), 18 deletions(-)

diff --git a/client.go b/client.go
index b5493e927..1f12d4ace 100644
--- a/client.go
+++ b/client.go
@@ -2975,12 +2975,12 @@ func (t *transport) RoundTrip(hc *HostClient, req *Request, resp *Response) (ret
 	closeConn := resetConnection || req.ConnectionClose() || resp.ConnectionClose() || isConnRST
 	if customStreamBody && resp.bodyStream != nil {
 		rbs := resp.bodyStream
-		resp.bodyStream = newCloseReader(rbs, func() error {
+		resp.bodyStream = newCloseReaderWithError(rbs, func(wErr error) error {
 			hc.releaseReader(br)
 			if r, ok := rbs.(*requestStream); ok {
 				releaseRequestStream(r)
 			}
-			if closeConn || resp.ConnectionClose() {
+			if closeConn || resp.ConnectionClose() || wErr != nil {
 				hc.closeConn(cc)
 			} else {
 				hc.releaseConn(cc)
diff --git a/http.go b/http.go
index 1ae8c3760..312e7f51a 100644
--- a/http.go
+++ b/http.go
@@ -321,26 +321,31 @@ func (resp *Response) BodyStream() io.Reader {
 }
 
 func (resp *Response) CloseBodyStream() error {
-	return resp.closeBodyStream()
+	return resp.closeBodyStream(nil)
+}
+
+type ReadCloserWithError interface {
+	io.Reader
+	CloseWithError(err error) error
 }
 
 type closeReader struct {
 	io.Reader
-	closeFunc func() error
+	closeFunc func(err error) error
 }
 
-func newCloseReader(r io.Reader, closeFunc func() error) io.ReadCloser {
+func newCloseReaderWithError(r io.Reader, closeFunc func(err error) error) ReadCloserWithError {
 	if r == nil {
 		panic(`BUG: reader is nil`)
 	}
 	return &closeReader{Reader: r, closeFunc: closeFunc}
 }
 
-func (c *closeReader) Close() error {
+func (c *closeReader) CloseWithError(err error) error {
 	if c.closeFunc == nil {
 		return nil
 	}
-	return c.closeFunc()
+	return c.closeFunc(err)
 }
 
 // BodyWriter returns writer for populating request body.
@@ -394,7 +399,7 @@ func (resp *Response) Body() []byte {
 		bodyBuf := resp.bodyBuffer()
 		bodyBuf.Reset()
 		_, err := copyZeroAlloc(bodyBuf, resp.bodyStream)
-		resp.closeBodyStream() //nolint:errcheck
+		resp.closeBodyStream(err) //nolint:errcheck
 		if err != nil {
 			bodyBuf.SetString(err.Error())
 		}
@@ -618,7 +623,7 @@ func (req *Request) BodyWriteTo(w io.Writer) error {
 func (resp *Response) BodyWriteTo(w io.Writer) error {
 	if resp.bodyStream != nil {
 		_, err := copyZeroAlloc(w, resp.bodyStream)
-		resp.closeBodyStream() //nolint:errcheck
+		resp.closeBodyStream(err) //nolint:errcheck
 		return err
 	}
 	_, err := w.Write(resp.bodyBytes())
@@ -629,13 +634,13 @@ func (resp *Response) BodyWriteTo(w io.Writer) error {
 //
 // It is safe re-using p after the function returns.
 func (resp *Response) AppendBody(p []byte) {
-	resp.closeBodyStream()     //nolint:errcheck
+	resp.closeBodyStream(nil)  //nolint:errcheck
 	resp.bodyBuffer().Write(p) //nolint:errcheck
 }
 
 // AppendBodyString appends s to response body.
 func (resp *Response) AppendBodyString(s string) {
-	resp.closeBodyStream()           //nolint:errcheck
+	resp.closeBodyStream(nil)        //nolint:errcheck
 	resp.bodyBuffer().WriteString(s) //nolint:errcheck
 }
 
@@ -643,7 +648,7 @@ func (resp *Response) AppendBodyString(s string) {
 //
 // It is safe re-using body argument after the function returns.
 func (resp *Response) SetBody(body []byte) {
-	resp.closeBodyStream() //nolint:errcheck
+	resp.closeBodyStream(nil) //nolint:errcheck
 	bodyBuf := resp.bodyBuffer()
 	bodyBuf.Reset()
 	bodyBuf.Write(body) //nolint:errcheck
@@ -651,7 +656,7 @@ func (resp *Response) SetBody(body []byte) {
 
 // SetBodyString sets response body.
 func (resp *Response) SetBodyString(body string) {
-	resp.closeBodyStream() //nolint:errcheck
+	resp.closeBodyStream(nil) //nolint:errcheck
 	bodyBuf := resp.bodyBuffer()
 	bodyBuf.Reset()
 	bodyBuf.WriteString(body) //nolint:errcheck
@@ -660,7 +665,7 @@ func (resp *Response) SetBodyString(body string) {
 // ResetBody resets response body.
 func (resp *Response) ResetBody() {
 	resp.bodyRaw = nil
-	resp.closeBodyStream() //nolint:errcheck
+	resp.closeBodyStream(nil) //nolint:errcheck
 	if resp.body != nil {
 		if resp.keepBodyBuffer {
 			resp.body.Reset()
@@ -700,7 +705,7 @@ func (resp *Response) ReleaseBody(size int) {
 		return
 	}
 	if cap(resp.body.B) > size {
-		resp.closeBodyStream() //nolint:errcheck
+		resp.closeBodyStream(nil) //nolint:errcheck
 		resp.body = nil
 	}
 }
@@ -734,7 +739,7 @@ func (resp *Response) SwapBody(body []byte) []byte {
 	if resp.bodyStream != nil {
 		bb.Reset()
 		_, err := copyZeroAlloc(bb, resp.bodyStream)
-		resp.closeBodyStream() //nolint:errcheck
+		resp.closeBodyStream(err) //nolint:errcheck
 		if err != nil {
 			bb.Reset()
 			bb.SetString(err.Error())
@@ -2061,7 +2066,7 @@ func (resp *Response) writeBodyStream(w *bufio.Writer, sendBody bool) (err error
 			}
 		}
 	}
-	errc := resp.closeBodyStream()
+	errc := resp.closeBodyStream(err)
 	if err == nil {
 		err = errc
 	}
@@ -2083,7 +2088,7 @@ func (req *Request) closeBodyStream() error {
 	return err
 }
 
-func (resp *Response) closeBodyStream() error {
+func (resp *Response) closeBodyStream(wErr error) error {
 	if resp.bodyStream == nil {
 		return nil
 	}
@@ -2091,6 +2096,9 @@ func (resp *Response) closeBodyStream() error {
 	if bsc, ok := resp.bodyStream.(io.Closer); ok {
 		err = bsc.Close()
 	}
+	if bsc, ok := resp.bodyStream.(ReadCloserWithError); ok {
+		err = bsc.CloseWithError(wErr)
+	}
 	if bsr, ok := resp.bodyStream.(*requestStream); ok {
 		releaseRequestStream(bsr)
 	}

From e821d30ead81bc75cff017024c2955e5e38e7d30 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 13:29:55 +0500
Subject: [PATCH 02/14] feat: add address in ErrDialTimeout

---
 tcpdialer.go | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index e8430cb9c..f1e6384e3 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -3,6 +3,7 @@ package fasthttp
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net"
 	"strconv"
 	"sync"
@@ -302,7 +303,7 @@ func (d *TCPDialer) dial(addr string, dualStack bool, timeout time.Duration) (ne
 		if err == nil {
 			return conn, nil
 		}
-		if err == ErrDialTimeout {
+		if errors.Is(err, ErrDialTimeout) {
 			return nil, err
 		}
 		idx++
@@ -316,7 +317,7 @@ func (d *TCPDialer) tryDial(
 ) (net.Conn, error) {
 	timeout := time.Until(deadline)
 	if timeout <= 0 {
-		return nil, ErrDialTimeout
+		return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
 	}
 
 	if concurrencyCh != nil {
@@ -332,7 +333,7 @@ func (d *TCPDialer) tryDial(
 			}
 			ReleaseTimer(tc)
 			if isTimeout {
-				return nil, ErrDialTimeout
+				return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
 			}
 		}
 		defer func() { <-concurrencyCh }()
@@ -347,7 +348,7 @@ func (d *TCPDialer) tryDial(
 	defer cancelCtx()
 	conn, err := dialer.DialContext(ctx, network, addr)
 	if err != nil && ctx.Err() == context.DeadlineExceeded {
-		return nil, ErrDialTimeout
+		return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
 	}
 	return conn, err
 }

From f57e2628e8777b88e0c5ddf8cefa78a14a560f41 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 13:39:28 +0500
Subject: [PATCH 03/14] feat: add address in any `tryDial` error

---
 tcpdialer.go | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index f1e6384e3..2f6c694fa 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -347,10 +347,13 @@ func (d *TCPDialer) tryDial(
 	ctx, cancelCtx := context.WithDeadline(context.Background(), deadline)
 	defer cancelCtx()
 	conn, err := dialer.DialContext(ctx, network, addr)
-	if err != nil && ctx.Err() == context.DeadlineExceeded {
-		return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+	if err != nil {
+		if ctx.Err() == context.DeadlineExceeded {
+			return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+		}
+		return nil, fmt.Errorf("error when dialing %s: %w", addr, err)
 	}
-	return conn, err
+	return conn, nil
 }
 
 // ErrDialTimeout is returned when TCP dialing is timed out.

From 05e68b1b60154ebadbe81aa27f01736fb84f8743 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 17:43:04 +0500
Subject: [PATCH 04/14] feat: use struct to wrap error with upstream info

---
 tcpdialer.go | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index 2f6c694fa..6d017e15e 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -317,7 +317,7 @@ func (d *TCPDialer) tryDial(
 ) (net.Conn, error) {
 	timeout := time.Until(deadline)
 	if timeout <= 0 {
-		return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+		return nil, wrapDialWithUpstream(ErrDialTimeout, addr)
 	}
 
 	if concurrencyCh != nil {
@@ -333,7 +333,7 @@ func (d *TCPDialer) tryDial(
 			}
 			ReleaseTimer(tc)
 			if isTimeout {
-				return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+				return nil, wrapDialWithUpstream(ErrDialTimeout, addr)
 			}
 		}
 		defer func() { <-concurrencyCh }()
@@ -349,9 +349,9 @@ func (d *TCPDialer) tryDial(
 	conn, err := dialer.DialContext(ctx, network, addr)
 	if err != nil {
 		if ctx.Err() == context.DeadlineExceeded {
-			return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+			return nil, wrapDialWithUpstream(ErrDialTimeout, addr)
 		}
-		return nil, fmt.Errorf("error when dialing %s: %w", addr, err)
+		return nil, wrapDialWithUpstream(err, addr)
 	}
 	return conn, nil
 }
@@ -359,6 +359,27 @@ func (d *TCPDialer) tryDial(
 // ErrDialTimeout is returned when TCP dialing is timed out.
 var ErrDialTimeout = errors.New("dialing to the given TCP address timed out")
 
+// ErrDialWithUpstream wraps dial error with upstream info
+type ErrDialWithUpstream struct {
+	Upstream string
+	wrapErr  error
+}
+
+func (e *ErrDialWithUpstream) Error() string {
+	return fmt.Sprintf("error when dialing %s: %s", e.Upstream, e.wrapErr)
+}
+
+func (e *ErrDialWithUpstream) Unwrap() error {
+	return e.wrapErr
+}
+
+func wrapDialWithUpstream(err error, upstream string) error {
+	return &ErrDialWithUpstream{
+		Upstream: upstream,
+		wrapErr:  err,
+	}
+}
+
 // DefaultDialTimeout is timeout used by Dial and DialDualStack
 // for establishing TCP connections.
 const DefaultDialTimeout = 3 * time.Second

From 3ab2f91b72b2bb1a7f5dd8e384c0aaa979d4fbe9 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 17:50:15 +0500
Subject: [PATCH 05/14] fix: lint

---
 tcpdialer.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index 6d017e15e..0ab88cad6 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -359,7 +359,7 @@ func (d *TCPDialer) tryDial(
 // ErrDialTimeout is returned when TCP dialing is timed out.
 var ErrDialTimeout = errors.New("dialing to the given TCP address timed out")
 
-// ErrDialWithUpstream wraps dial error with upstream info
+// ErrDialWithUpstream wraps dial error with upstream info.
 type ErrDialWithUpstream struct {
 	Upstream string
 	wrapErr  error

From 2ba2e3471198d44481547c386fd3064b8daa89f4 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 17:54:45 +0500
Subject: [PATCH 06/14] fix: wrapped Error() method

---
 tcpdialer.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index 0ab88cad6..5f6081502 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -366,7 +366,7 @@ type ErrDialWithUpstream struct {
 }
 
 func (e *ErrDialWithUpstream) Error() string {
-	return fmt.Sprintf("error when dialing %s: %s", e.Upstream, e.wrapErr)
+	return fmt.Sprintf("error when dialing %s: %s", e.Upstream, e.wrapErr.Error())
 }
 
 func (e *ErrDialWithUpstream) Unwrap() error {

From 05fbdc792849b8fbfc4cbbd8b79fa853a482f0a4 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Tue, 23 Apr 2024 09:53:40 +0500
Subject: [PATCH 07/14] docs: add example to ErrDialWithUpstream

---
 tcpdialer.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tcpdialer.go b/tcpdialer.go
index 5f6081502..f6212b5d8 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -360,6 +360,14 @@ func (d *TCPDialer) tryDial(
 var ErrDialTimeout = errors.New("dialing to the given TCP address timed out")
 
 // ErrDialWithUpstream wraps dial error with upstream info.
+//
+// Should use errors.As to get upstream information from error:
+//
+// var dialErr *fasthttp.ErrDialWithUpstream
+//
+//	if errors.As(err, &dialErr) {
+//	  upstream = dialErr.Upstream
+//	}
 type ErrDialWithUpstream struct {
 	Upstream string
 	wrapErr  error

From ba48784a965fb257c7dfc8cbac0b3fc94c54f770 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 13:29:55 +0500
Subject: [PATCH 08/14] feat: add address in ErrDialTimeout

---
 tcpdialer.go | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index e8430cb9c..f1e6384e3 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -3,6 +3,7 @@ package fasthttp
 import (
 	"context"
 	"errors"
+	"fmt"
 	"net"
 	"strconv"
 	"sync"
@@ -302,7 +303,7 @@ func (d *TCPDialer) dial(addr string, dualStack bool, timeout time.Duration) (ne
 		if err == nil {
 			return conn, nil
 		}
-		if err == ErrDialTimeout {
+		if errors.Is(err, ErrDialTimeout) {
 			return nil, err
 		}
 		idx++
@@ -316,7 +317,7 @@ func (d *TCPDialer) tryDial(
 ) (net.Conn, error) {
 	timeout := time.Until(deadline)
 	if timeout <= 0 {
-		return nil, ErrDialTimeout
+		return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
 	}
 
 	if concurrencyCh != nil {
@@ -332,7 +333,7 @@ func (d *TCPDialer) tryDial(
 			}
 			ReleaseTimer(tc)
 			if isTimeout {
-				return nil, ErrDialTimeout
+				return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
 			}
 		}
 		defer func() { <-concurrencyCh }()
@@ -347,7 +348,7 @@ func (d *TCPDialer) tryDial(
 	defer cancelCtx()
 	conn, err := dialer.DialContext(ctx, network, addr)
 	if err != nil && ctx.Err() == context.DeadlineExceeded {
-		return nil, ErrDialTimeout
+		return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
 	}
 	return conn, err
 }

From 0f421eb4a871af969aafefb53d7cf4aabceba704 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 13:39:28 +0500
Subject: [PATCH 09/14] feat: add address in any `tryDial` error

---
 tcpdialer.go | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index f1e6384e3..2f6c694fa 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -347,10 +347,13 @@ func (d *TCPDialer) tryDial(
 	ctx, cancelCtx := context.WithDeadline(context.Background(), deadline)
 	defer cancelCtx()
 	conn, err := dialer.DialContext(ctx, network, addr)
-	if err != nil && ctx.Err() == context.DeadlineExceeded {
-		return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+	if err != nil {
+		if ctx.Err() == context.DeadlineExceeded {
+			return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+		}
+		return nil, fmt.Errorf("error when dialing %s: %w", addr, err)
 	}
-	return conn, err
+	return conn, nil
 }
 
 // ErrDialTimeout is returned when TCP dialing is timed out.

From b03bf567e45453603f86fc9175fd4828bc8c9239 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 17:43:04 +0500
Subject: [PATCH 10/14] feat: use struct to wrap error with upstream info

---
 tcpdialer.go | 29 +++++++++++++++++++++++++----
 1 file changed, 25 insertions(+), 4 deletions(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index 2f6c694fa..6d017e15e 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -317,7 +317,7 @@ func (d *TCPDialer) tryDial(
 ) (net.Conn, error) {
 	timeout := time.Until(deadline)
 	if timeout <= 0 {
-		return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+		return nil, wrapDialWithUpstream(ErrDialTimeout, addr)
 	}
 
 	if concurrencyCh != nil {
@@ -333,7 +333,7 @@ func (d *TCPDialer) tryDial(
 			}
 			ReleaseTimer(tc)
 			if isTimeout {
-				return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+				return nil, wrapDialWithUpstream(ErrDialTimeout, addr)
 			}
 		}
 		defer func() { <-concurrencyCh }()
@@ -349,9 +349,9 @@ func (d *TCPDialer) tryDial(
 	conn, err := dialer.DialContext(ctx, network, addr)
 	if err != nil {
 		if ctx.Err() == context.DeadlineExceeded {
-			return nil, fmt.Errorf("error when dialing %s: %w", addr, ErrDialTimeout)
+			return nil, wrapDialWithUpstream(ErrDialTimeout, addr)
 		}
-		return nil, fmt.Errorf("error when dialing %s: %w", addr, err)
+		return nil, wrapDialWithUpstream(err, addr)
 	}
 	return conn, nil
 }
@@ -359,6 +359,27 @@ func (d *TCPDialer) tryDial(
 // ErrDialTimeout is returned when TCP dialing is timed out.
 var ErrDialTimeout = errors.New("dialing to the given TCP address timed out")
 
+// ErrDialWithUpstream wraps dial error with upstream info
+type ErrDialWithUpstream struct {
+	Upstream string
+	wrapErr  error
+}
+
+func (e *ErrDialWithUpstream) Error() string {
+	return fmt.Sprintf("error when dialing %s: %s", e.Upstream, e.wrapErr)
+}
+
+func (e *ErrDialWithUpstream) Unwrap() error {
+	return e.wrapErr
+}
+
+func wrapDialWithUpstream(err error, upstream string) error {
+	return &ErrDialWithUpstream{
+		Upstream: upstream,
+		wrapErr:  err,
+	}
+}
+
 // DefaultDialTimeout is timeout used by Dial and DialDualStack
 // for establishing TCP connections.
 const DefaultDialTimeout = 3 * time.Second

From c186a1e6f20eae4a3c1ab5c4fa088d5a40a6a9be Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 17:50:15 +0500
Subject: [PATCH 11/14] fix: lint

---
 tcpdialer.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index 6d017e15e..0ab88cad6 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -359,7 +359,7 @@ func (d *TCPDialer) tryDial(
 // ErrDialTimeout is returned when TCP dialing is timed out.
 var ErrDialTimeout = errors.New("dialing to the given TCP address timed out")
 
-// ErrDialWithUpstream wraps dial error with upstream info
+// ErrDialWithUpstream wraps dial error with upstream info.
 type ErrDialWithUpstream struct {
 	Upstream string
 	wrapErr  error

From c0cfa3115570b7436be8ab4c0974cabd077d8674 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Mon, 22 Apr 2024 17:54:45 +0500
Subject: [PATCH 12/14] fix: wrapped Error() method

---
 tcpdialer.go | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index 0ab88cad6..5f6081502 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -366,7 +366,7 @@ type ErrDialWithUpstream struct {
 }
 
 func (e *ErrDialWithUpstream) Error() string {
-	return fmt.Sprintf("error when dialing %s: %s", e.Upstream, e.wrapErr)
+	return fmt.Sprintf("error when dialing %s: %s", e.Upstream, e.wrapErr.Error())
 }
 
 func (e *ErrDialWithUpstream) Unwrap() error {

From 18c9bbfff6e23ae099ed7ed70c7b3d11b0425ff0 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Tue, 23 Apr 2024 09:53:40 +0500
Subject: [PATCH 13/14] docs: add example to ErrDialWithUpstream

---
 tcpdialer.go | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/tcpdialer.go b/tcpdialer.go
index 5f6081502..f6212b5d8 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -360,6 +360,14 @@ func (d *TCPDialer) tryDial(
 var ErrDialTimeout = errors.New("dialing to the given TCP address timed out")
 
 // ErrDialWithUpstream wraps dial error with upstream info.
+//
+// Should use errors.As to get upstream information from error:
+//
+// var dialErr *fasthttp.ErrDialWithUpstream
+//
+//	if errors.As(err, &dialErr) {
+//	  upstream = dialErr.Upstream
+//	}
 type ErrDialWithUpstream struct {
 	Upstream string
 	wrapErr  error

From e38d6f10b8e6ea753f985ccf992b846d6366ae31 Mon Sep 17 00:00:00 2001
From: Max Denushev <denushev@tochka.com>
Date: Thu, 2 May 2024 10:06:09 +0700
Subject: [PATCH 14/14] docs: fix example for ErrDialWithUpstream

---
 tcpdialer.go | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/tcpdialer.go b/tcpdialer.go
index f6212b5d8..e5f06bd01 100644
--- a/tcpdialer.go
+++ b/tcpdialer.go
@@ -363,10 +363,12 @@ var ErrDialTimeout = errors.New("dialing to the given TCP address timed out")
 //
 // Should use errors.As to get upstream information from error:
 //
-// var dialErr *fasthttp.ErrDialWithUpstream
+//	hc := fasthttp.HostClient{Addr: "foo.com,bar.com"}
+//	err := hc.Do(req, res)
 //
+//	var dialErr *fasthttp.ErrDialWithUpstream
 //	if errors.As(err, &dialErr) {
-//	  upstream = dialErr.Upstream
+//		upstream = dialErr.Upstream // 34.206.39.153:80
 //	}
 type ErrDialWithUpstream struct {
 	Upstream string