From ddd36645b25c97651deb81c092c7669efabd959e Mon Sep 17 00:00:00 2001
From: Jorropo <jorropo.pgm@gmail.com>
Date: Thu, 31 Mar 2022 23:43:27 +0200
Subject: [PATCH] feat: update the error parsing for go-ipld-format to v0.4.0

This commit was moved from ipfs/go-ipfs-http-client@296534fd1647a1ec9cae08314daf41ec96d55763
---
 client/httpapi/errors.go      | 54 +++++++++++++++++++++--------------
 client/httpapi/errors_test.go | 14 +++++++--
 2 files changed, 44 insertions(+), 24 deletions(-)

diff --git a/client/httpapi/errors.go b/client/httpapi/errors.go
index a527e5452..f42d92575 100644
--- a/client/httpapi/errors.go
+++ b/client/httpapi/errors.go
@@ -45,6 +45,18 @@ func parseIPLDNotFoundWithFallbackToError(msg error) error {
 	return msg
 }
 
+// Use a string to move it into RODATA
+// print("".join("\\x01" if chr(i) not in string.ascii_letters + string.digits else "\\x00" for i in range(ord('z')+1)))
+const notAsciiLetterOrDigitsLUT = "\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x01\x01\x01\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x01\x01\x01\x01\x01\x01\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00"
+
+func notAsciiLetterOrDigits(r rune) bool {
+	if r > 'z' {
+		return true
+	}
+
+	return notAsciiLetterOrDigitsLUT[r] > 0
+}
+
 // This file handle parsing and returning the correct ABI based errors from error messages
 //lint:ignore ST1008 this function is not using the error as a mean to return failure but it massages it to return the correct type
 func parseIPLDNotFound(msg string) (error, bool) {
@@ -53,46 +65,46 @@ func parseIPLDNotFound(msg string) (error, bool) {
 	}
 
 	// The patern we search for is:
-	//   node not found (fallback)
-	// or
-	//   CID not found (here we parse the CID)
-	notFoundIndex := strings.LastIndex(msg, " not found")
+	const ipldErrNotFoundKey = "ipld: could not find " /*CID*/
+	// We try to parse the CID, if it's invalid we give up and return a simple text error.
+	// We also accept "node" in place of the CID because that means it's an Undefined CID.
 
-	if notFoundIndex == -1 {
-		// Unknown, ot found not found
+	keyIndex := strings.Index(msg, ipldErrNotFoundKey)
+
+	if keyIndex < 0 { // Unknown error
 		return nil, false
 	}
 
-	preNotFound := msg[:notFoundIndex]
+	cidStart := keyIndex + len(ipldErrNotFoundKey)
 
+	msgPostKey := msg[cidStart:]
 	var c cid.Cid
-	var preIndex int
-	if strings.HasSuffix(preNotFound, "node") {
+	var postIndex int
+	if strings.HasPrefix(msgPostKey, "node") {
 		// Fallback case
 		c = cid.Undef
-		preIndex = notFoundIndex - len("node")
+		postIndex = len("node")
 	} else {
-		// Assume that CIDs does not include whitespace to pull out the CID
-		preIndex = strings.LastIndexByte(preNotFound, ' ')
-		// + 1 is to normalise not founds to zeros and point to the start of the CID, not the previous space
-		preIndex++
+		// Assume that CIDs only contain a-zA-Z0-9 characters.
+		// This is true because go-ipld-format use go-cid#Cid.String which use base{3{2,6},58}.
+		postIndex = strings.IndexFunc(msgPostKey, notAsciiLetterOrDigits)
+		if postIndex < 0 {
+			postIndex = len(msgPostKey)
+		}
+
 		var err error
-		c, err = cid.Decode(preNotFound[preIndex:])
+		c, err = cid.Decode(msgPostKey[:postIndex])
 		if err != nil {
 			// Unknown
 			return nil, false
 		}
 	}
 
-	postIndex := notFoundIndex + len(" not found")
-
 	err := ipld.ErrNotFound{Cid: c}
-
-	pre := msg[:preIndex]
-	post := msg[postIndex:]
+	pre := msg[:keyIndex]
+	post := msgPostKey[postIndex:]
 
 	if len(pre) > 0 || len(post) > 0 {
-		// We have some text to wrap arround the ErrNotFound one
 		return prePostWrappedNotFoundError{
 			pre:     pre,
 			post:    post,
diff --git a/client/httpapi/errors_test.go b/client/httpapi/errors_test.go
index 502c10966..1b7de8798 100644
--- a/client/httpapi/errors_test.go
+++ b/client/httpapi/errors_test.go
@@ -3,6 +3,7 @@ package httpapi
 import (
 	"errors"
 	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/ipfs/go-cid"
@@ -42,9 +43,8 @@ func TestParseIPLDNotFound(t *testing.T) {
 		"%w is wrong",
 	} {
 		for _, err := range [...]error{
-			errors.New("file not found"),
-			errors.New(" not found"),
-			errors.New("Bad_CID not found"),
+			errors.New("ipld: could not find "),
+			errors.New("ipld: could not find Bad_CID"),
 			errors.New("network connection timeout"),
 			ipld.ErrNotFound{Cid: cid.Undef},
 			ipld.ErrNotFound{Cid: cid.NewCidV0(randomSha256MH)},
@@ -58,3 +58,11 @@ func TestParseIPLDNotFound(t *testing.T) {
 		}
 	}
 }
+
+func TestNotAsciiLetterOrDigits(t *testing.T) {
+	for i := rune(0); i <= 256; i++ {
+		if notAsciiLetterOrDigits(i) != !strings.ContainsAny(string(i), "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789") {
+			t.Errorf("%q is incorrectly identified", i)
+		}
+	}
+}