[bugfix] Add back removed ValidateRequest() before backoff-retry loop (#1805)v0.9.0-rc2

* add back removed ValidateRequest() before backoff-retry loop

Signed-off-by: kim <grufwub@gmail.com>

* include response body in error response log

Signed-off-by: kim <grufwub@gmail.com>

* improved error response body draining

Signed-off-by: kim <grufwub@gmail.com>

* add more code commenting

Signed-off-by: kim <grufwub@gmail.com>

* move new error response logic to gtserror, handle instead in transport.Transport{} impl

Signed-off-by: kim <grufwub@gmail.com>

* appease ye oh mighty linter

Signed-off-by: kim <grufwub@gmail.com>

* fix mockhttpclient not setting request in http response

Signed-off-by: kim <grufwub@gmail.com>

---------

Signed-off-by: kim <grufwub@gmail.com>

4 files changed, 201 insertions, 2 deletions

diff --git a/internal/gtserror/error.go b/internal/gtserror/error.go
index 56e546cf1..e68ed7d3b 100644
--- a/internal/gtserror/error.go
+++ b/internal/gtserror/error.go
@@ -34,8 +34,8 @@ const (
 	notFoundKey
 	errorTypeKey
 
-	// error types
-	TypeSMTP ErrorType = "smtp" // smtp (mail) error
+	// Types returnable from Type(...).
+	TypeSMTP ErrorType = "smtp" // smtp (mail)
 )
 
 // StatusCode checks error for a stored status code value. For example
diff --git a/internal/gtserror/new.go b/internal/gtserror/new.go
new file mode 100644
index 000000000..ad20e5cac
--- /dev/null
+++ b/internal/gtserror/new.go
@@ -0,0 +1,66 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package gtserror
+
+import (
+	"errors"
+	"net/http"
+
+	"codeberg.org/gruf/go-byteutil"
+)
+
+// NewResponseError crafts an error from provided HTTP response
+// including the method, status and body (if any provided). This
+// will also wrap the returned error using WithStatusCode().
+func NewResponseError(rsp *http.Response) error {
+	var buf byteutil.Buffer
+
+	// Get URL string ahead of time.
+	urlStr := rsp.Request.URL.String()
+
+	// Alloc guesstimate of required buf size.
+	buf.Guarantee(0 +
+		len(rsp.Request.Method) +
+		12 + //  request to
+		len(urlStr) +
+		17 + //  failed: status="
+		len(rsp.Status) +
+		8 + // " body="
+		256 + // max body size
+		1, // "
+	)
+
+	// Build error message string without
+	// using "fmt", as chances are this will
+	// be used in a hot code path and we
+	// know all the incoming types involved.
+	_, _ = buf.WriteString(rsp.Request.Method)
+	_, _ = buf.WriteString(" request to ")
+	_, _ = buf.WriteString(urlStr)
+	_, _ = buf.WriteString(" failed: status=\"")
+	_, _ = buf.WriteString(rsp.Status)
+	_, _ = buf.WriteString("\" body=\"")
+	_, _ = buf.WriteString(drainBody(rsp.Body, 256))
+	_, _ = buf.WriteString("\"")
+
+	// Create new error from msg.
+	err := errors.New(buf.String())
+
+	// Wrap error to provide status code.
+	return WithStatusCode(err, rsp.StatusCode)
+}
diff --git a/internal/gtserror/new_test.go b/internal/gtserror/new_test.go
new file mode 100644
index 000000000..b0824b5a7
--- /dev/null
+++ b/internal/gtserror/new_test.go
@@ -0,0 +1,91 @@
+package gtserror_test
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"net/url"
+	"strings"
+	"testing"
+
+	"github.com/superseriousbusiness/gotosocial/internal/gtserror"
+)
+
+func TestResponseError(t *testing.T) {
+	testResponseError(t, http.Response{
+		Body: toBody(`{"error": "user not found"}`),
+		Request: &http.Request{
+			Method: "GET",
+			URL:    toURL("https://google.com/users/sundar"),
+		},
+		Status: "404 Not Found",
+	})
+	testResponseError(t, http.Response{
+		Body: toBody("Unauthorized"),
+		Request: &http.Request{
+			Method: "POST",
+			URL:    toURL("https://google.com/inbox"),
+		},
+		Status: "401 Unauthorized",
+	})
+	testResponseError(t, http.Response{
+		Body: toBody(""),
+		Request: &http.Request{
+			Method: "GET",
+			URL:    toURL("https://google.com/users/sundar"),
+		},
+		Status: "404 Not Found",
+	})
+}
+
+func testResponseError(t *testing.T, rsp http.Response) {
+	var body string
+	if rsp.Body == http.NoBody {
+		body = "<empty>"
+	} else {
+		var b []byte
+		rsp.Body, b = copyBody(rsp.Body)
+		trunc := len(b)
+		if trunc > 256 {
+			trunc = 256
+		}
+		body = string(b[:trunc])
+	}
+	expect := fmt.Sprintf(
+		"%s request to %s failed: status=\"%s\" body=\"%s\"",
+		rsp.Request.Method,
+		rsp.Request.URL.String(),
+		rsp.Status,
+		body,
+	)
+	err := gtserror.NewResponseError(&rsp)
+	if str := err.Error(); str != expect {
+		t.Errorf("unexpected error string: recv=%q expct=%q", str, expect)
+	}
+}
+
+func toURL(u string) *url.URL {
+	url, err := url.Parse(u)
+	if err != nil {
+		panic(err)
+	}
+	return url
+}
+
+func toBody(s string) io.ReadCloser {
+	if s == "" {
+		return http.NoBody
+	}
+	r := strings.NewReader(s)
+	return io.NopCloser(r)
+}
+
+func copyBody(rc io.ReadCloser) (io.ReadCloser, []byte) {
+	b, err := io.ReadAll(rc)
+	if err != nil {
+		panic(err)
+	}
+	r := bytes.NewReader(b)
+	return io.NopCloser(r), b
+}
diff --git a/internal/gtserror/util.go b/internal/gtserror/util.go
new file mode 100644
index 000000000..635518b76
--- /dev/null
+++ b/internal/gtserror/util.go
@@ -0,0 +1,42 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package gtserror
+
+import (
+	"io"
+
+	"codeberg.org/gruf/go-byteutil"
+)
+
+// drainBody will produce a truncated output of the content
+// of given io.ReadCloser body, useful for logs / errors.
+func drainBody(body io.ReadCloser, trunc int) string {
+	// Limit response to 'trunc' bytes.
+	buf := make([]byte, trunc)
+
+	// Read body into err buffer.
+	n, _ := io.ReadFull(body, buf)
+
+	if n == 0 {
+		// No error body, return
+		// reasonable error str.
+		return "<empty>"
+	}
+
+	return byteutil.B2S(buf[:n])
+}