fix(conf): support equal signs in property values (#5392)

Co-authored-by: liaogs <liaoguoshun@qq.com>

core/conf/properties.go

@@ -45,7 +45,7 @@ func LoadProperties(filename string, opts ...Option) (Properties, error) {
 
 	raw := make(map[string]string)
 	for i := range lines {
-		pair := strings.Split(lines[i], "=")
+		pair := strings.SplitN(lines[i], "=", 2)
 		if len(pair) != 2 {
 			// invalid property format
 			return nil, &PropertyError{

core/conf/properties_test.go

@@ -92,3 +92,70 @@ func TestLoadBadFile(t *testing.T) {
 	_, err := LoadProperties("nosuchfile")
 	assert.NotNil(t, err)
 }
+
+func TestProperties_valueWithEqualSymbols(t *testing.T) {
+	text := `# test with equal symbols in value
+	db.url=postgres://localhost:5432/db?param=value
+	math.equation=a=b=c
+	base64.data=SGVsbG8=World=Test=
+	url.with.params=http://example.com?foo=bar&baz=qux
+	empty.value=
+	key.with.space = value = with = equals`
+	tmpfile, err := fs.TempFilenameWithText(text)
+	assert.Nil(t, err)
+	defer os.Remove(tmpfile)
+
+	props, err := LoadProperties(tmpfile)
+	assert.Nil(t, err)
+	assert.Equal(t, "postgres://localhost:5432/db?param=value", props.GetString("db.url"))
+	assert.Equal(t, "a=b=c", props.GetString("math.equation"))
+	assert.Equal(t, "SGVsbG8=World=Test=", props.GetString("base64.data"))
+	assert.Equal(t, "http://example.com?foo=bar&baz=qux", props.GetString("url.with.params"))
+	assert.Equal(t, "", props.GetString("empty.value"))
+	assert.Equal(t, "value = with = equals", props.GetString("key.with.space"))
+}
+
+func TestProperties_edgeCases(t *testing.T) {
+	tests := []struct {
+		name    string
+		content string
+		wantErr bool
+		errMsg  string
+	}{
+		{
+			name:    "no equal sign",
+			content: "invalid line without equal",
+			wantErr: true,
+		},
+		{
+			name:    "only equal sign",
+			content: "=",
+			wantErr: false, // "=" 会被解析为空 key 和空 value，len(pair) == 2，是合法的
+		},
+		{
+			name:    "empty key",
+			content: "=value",
+			wantErr: false, // 空 key 也会被 trim，但 len(pair) == 2 所以不会报错
+		},
+		{
+			name:    "equal at end",
+			content: "key.name=",
+			wantErr: false, // 空 value 是合法的
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			tmpfile, err := fs.TempFilenameWithText(tt.content)
+			assert.Nil(t, err)
+			defer os.Remove(tmpfile)
+
+			_, err = LoadProperties(tmpfile)
+			if tt.wantErr {
+				assert.NotNil(t, err, "expected error for case: %s", tt.name)
+			} else {
+				assert.Nil(t, err, "unexpected error for case: %s", tt.name)
+			}
+		})
+	}
+}