Bug Report: JSON Deserialization Case Sensitivity Issue in Go

[acczefly]

Go version

go version go1.22.3 darwin/arm64

Output of go env in your module/workspace:

GO111MODULE='on'
GOARCH='arm64'
GOBIN=''
GOCACHE='/Users/xxxxxx/Library/Caches/go-build'
GOENV='/Users/xxxxxx/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFLAGS=''
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMODCACHE='/opt/workspace/golang/pkg/mod'
GONOPROXY=''
GONOSUMDB=''
GOOS='darwin'
GOPATH='/opt/workspace/golang'
GOPRIVATE=''
GOPROXY='direct'
GOROOT='/opt/homebrew/Cellar/go/1.22.3/libexec'
GOSUMDB='sum.golang.org'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/opt/homebrew/Cellar/go/1.22.3/libexec/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.22.3'
GCCGO='gccgo'
AR='ar'
CC='cc'
CXX='c++'
CGO_ENABLED='1'
GOMOD='/opt/tmp/go.mod'
GOWORK=''
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
PKG_CONFIG='pkg-config'
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/3q/0tmgj6rd7d15y9lgxmykjnp40000gn/T/go-build860661036=/tmp/go-build -gno-record-gcc-switches -fno-common'

What did you do?

package main

import (
	"encoding/json"
	"fmt"
)

type Ticker1 struct {
	// EventType string `json:"e"`
	EventTime int64 `json:"E"`
}

type Ticker2 struct {
	EventType string `json:"e"`
	EventTime int64 `json:"E"`
}

func main(){
	raw := `{"A":"0.099912","B":"0.089148","C":1716983452351,"E":1716983452351,"F":1364420,"L":1447324,"O":1716897052351,"P":"-1.994","Q":"0.00350000","a":"3821.95000000","b":"3821.93000000","c":"3821.94000000","e":"24hrTicker","h":"4667.30000000","l":"3100.00000000","n":82905,"o":"3899.69000000","p":"-77.75000000","q":"19657826.75182800","s":"ETHUSDT","v":"5113.89840000","w":"3844.00025464","x":"3899.69000000"}`

	var ticker1 Ticker1
	fmt.Println(json.Unmarshal([]byte(raw), &ticker1))

	var ticker2 Ticker2
	fmt.Println(json.Unmarshal([]byte(raw), &ticker2))
}

What did you see happen?

json: cannot unmarshal string into Go struct field Ticker1.E of type int64

What did you expect to see?

[acczefly]

Title: json: cannot unmarshal string into Go struct field Ticker.E of type int64

Description:
I have encountered an issue with the encoding/json package in Go, where JSON deserialization does not correctly handle the case sensitivity of fields in strings. Specifically, when deserializing a JSON object, the field names in the JSON string are case-sensitive and do not match the struct fields if there is a difference in case.

[seankhliao]

Duplicate of #14750