// Copyright (c) HashiCorp, Inc. // SPDX-License-Identifier: BUSL-1.1 package wasm import ( "encoding/json" "fmt" "net/url" "strings" "testing" "time" envoy_core_v3 "github.com/envoyproxy/go-control-plane/envoy/config/core/v3" envoy_listener_v3 "github.com/envoyproxy/go-control-plane/envoy/config/listener/v3" envoy_http_wasm_v3 "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/http/wasm/v3" envoy_http_v3 "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/network/http_connection_manager/v3" envoy_network_wasm_v3 "github.com/envoyproxy/go-control-plane/envoy/extensions/filters/network/wasm/v3" envoy_wasm_v3 "github.com/envoyproxy/go-control-plane/envoy/extensions/wasm/v3" "github.com/stretchr/testify/require" "google.golang.org/protobuf/encoding/protojson" "google.golang.org/protobuf/proto" "google.golang.org/protobuf/types/known/anypb" "google.golang.org/protobuf/types/known/durationpb" "google.golang.org/protobuf/types/known/wrapperspb" "github.com/hashicorp/consul/acl" "github.com/hashicorp/consul/api" "github.com/hashicorp/consul/envoyextensions/extensioncommon" "github.com/hashicorp/consul/proto/private/prototest" ) func TestHttpWasmExtension(t *testing.T) { t.Parallel() cases := map[string]struct { extName string canApply bool cfg func(string, bool) *testWasmConfig rtCfg func(string, bool) *extensioncommon.RuntimeConfig isInboundFilter bool errStr string debug bool }{ "remote file": { extName: api.BuiltinWasmExtension, canApply: true, cfg: func(proto string, ent bool) *testWasmConfig { return makeTestWasmConfig(proto, ent) }, rtCfg: func(proto string, ent bool) *extensioncommon.RuntimeConfig { return makeTestRuntimeConfig(proto, ent) }, isInboundFilter: true, }, "local file": { extName: api.BuiltinWasmExtension, canApply: true, cfg: func(proto string, ent bool) *testWasmConfig { cfg := newTestWasmConfig(proto, ent) cfg.ListenerType = "inbound" cfg.PluginConfig.VmConfig.Code.Local.Filename = "plugin.wasm" return cfg }, rtCfg: func(proto string, ent bool) *extensioncommon.RuntimeConfig { return makeTestRuntimeConfig(proto, ent) }, isInboundFilter: true, }, "inbound filters ignored": { extName: api.BuiltinWasmExtension, canApply: true, cfg: func(proto string, ent bool) *testWasmConfig { return makeTestWasmConfig(proto, ent) }, rtCfg: func(proto string, ent bool) *extensioncommon.RuntimeConfig { return makeTestRuntimeConfig(proto, ent) }, isInboundFilter: false, }, "no cluster for remote file": { extName: api.BuiltinWasmExtension, canApply: true, cfg: func(proto string, ent bool) *testWasmConfig { return makeTestWasmConfig(proto, ent) }, rtCfg: func(proto string, ent bool) *extensioncommon.RuntimeConfig { rt := makeTestRuntimeConfig(proto, ent) rt.Upstreams = nil return rt }, isInboundFilter: true, errStr: "no upstream found for remote service", }, "protocol mismatch": { extName: api.BuiltinWasmExtension, canApply: false, cfg: func(proto string, ent bool) *testWasmConfig { return makeTestWasmConfig(proto, ent) }, rtCfg: func(proto string, ent bool) *extensioncommon.RuntimeConfig { rt := makeTestRuntimeConfig(proto, ent) switch proto { case "http": rt.Protocol = "tcp" case "tcp": rt.Protocol = "http" } return rt }, isInboundFilter: true, }, } for _, enterprise := range []bool{false, true} { for _, protocol := range []string{"tcp", "http"} { for name, c := range cases { c := c t.Run(fmt.Sprintf("%s_%s_ent_%t", name, protocol, enterprise), func(t *testing.T) { cfg := c.cfg(protocol, enterprise) rtCfg := c.rtCfg(protocol, enterprise) rtCfg.EnvoyExtension = api.EnvoyExtension{ Name: c.extName, Arguments: cfg.toMap(t), } w, err := construct(rtCfg.EnvoyExtension) require.NoError(t, err) require.Equal(t, c.canApply, w.CanApply(rtCfg)) if !c.canApply { return } var inputFilters []*envoy_listener_v3.Filter if protocol == "http" { inputFilters = append(inputFilters, makeHttpConMgr(t, makeTestHttpFilters())) } else { inputFilters = makeTestFilters() } obsFilters, err := w.PatchFilters(rtCfg, inputFilters, c.isInboundFilter) if c.errStr == "" { require.NoError(t, err) expFilters := cfg.expFilters(t) if !cfg.matchesDirection(c.isInboundFilter) { // If the listener type does not match the filter direction then the // filter should not be applied and the output should match the input. expFilters = inputFilters } if c.debug { t.Logf("cfg =\n%s\n\n", cfg.toJSON(t)) require.Equal(t, len(expFilters), len(obsFilters)) for idx, expFilter := range expFilters { t.Logf("expFilterJSON[%d] =\n%s\n\n", idx, protoToJSON(t, expFilter)) t.Logf("obsfilterJSON[%d] =\n%s\n\n", idx, protoToJSON(t, obsFilters[idx])) } } prototest.AssertDeepEqual(t, expFilters, obsFilters) } else { require.Error(t, err) require.Contains(t, err.Error(), c.errStr) } }) } } } } func TestWasmConstructor(t *testing.T) { t.Parallel() cases := map[string]struct { name string args func(string, bool) map[string]any errStr string }{ "with no arguments": { name: api.BuiltinWasmExtension, args: func(_ string, _ bool) map[string]any { return nil }, errStr: "VmConfig.Code must provide exactly one of Local or Remote data source", }, "invalid protocol": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.Protocol = "invalid" return cfg.toMap(t) }, errStr: `unsupported Protocol "invalid", expected "tcp" or "http"`, }, "invalid proxy type": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.ProxyType = "invalid" return cfg.toMap(t) }, errStr: "unsupported ProxyType", }, "invalid listener type": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.ListenerType = "invalid" return cfg.toMap(t) }, errStr: `unsupported ListenerType "invalid", expected "inbound" or "outbound"`, }, "invalid runtime": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Runtime = "invalid" return cfg.toMap(t) }, errStr: "unsupported runtime", }, "both local and remote files": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Local.Filename = "plugin.wasm" cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Service.Name = "file-server" cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.URI = "http://file-server/plugin.wasm" return cfg.toMap(t) }, errStr: "VmConfig.Code must provide exactly one of Local or Remote data source", }, "service and uri required for remote files": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Service.Name = "file-server" return cfg.toMap(t) }, errStr: "both Service and URI are required for Remote data sources", }, "no sha for remote file": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Service.Name = "file-server" cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.URI = "http://file-server/plugin.wasm" return cfg.toMap(t) }, errStr: "SHA256 checksum is required for Remote data sources", }, "invalid url for remote file": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Service.Name = "file-server" cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.URI = "://bogus.url.com/error" return cfg.toMap(t) }, errStr: `invalid HttpURI.URI: parse "://bogus.url.com/error": missing protocol scheme`, }, "decoding error": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { a := makeTestWasmConfig(proto, ent).toMap(t) setField(a, "PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.BaseInterval", 1000) return a }, errStr: "got unconvertible type", }, "invalid http timeout": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Timeout = "invalid" return cfg.toMap(t) }, errStr: `failed to parse HttpURI.Timeout "invalid" as a duration`, }, "invalid num retries": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.NumRetries = -1 return cfg.toMap(t) }, errStr: "RetryPolicy.NumRetries must be greater than or equal to 0", }, "invalid base interval": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.BaseInterval = "0s" return cfg.toMap(t) }, errStr: `RetryBackOff.BaseInterval "0s" must be greater than zero and less than or equal to RetryBackOff.MaxInterval`, }, "invalid max interval": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.BaseInterval = "10s" cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.MaxInterval = "5s" return cfg.toMap(t) }, errStr: `RetryBackOff.MaxInterval "5s" must be greater than or equal to RetryBackOff.BaseInterval "10s"`, }, "invalid base interval duration": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.BaseInterval = "invalid" return cfg.toMap(t) }, errStr: `failed to parse RetryBackOff.BaseInterval "invalid"`, }, "invalid max interval duration": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { cfg := newTestWasmConfig(proto, ent) cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.MaxInterval = "invalid" return cfg.toMap(t) }, errStr: `failed to parse RetryBackOff.MaxInterval "invalid"`, }, "invalid extension name": { name: "invalid", args: func(proto string, ent bool) map[string]any { return newTestWasmConfig(proto, ent).toMap(t) }, errStr: `expected extension name "builtin/wasm" but got "invalid"`, }, "valid configuration": { name: api.BuiltinWasmExtension, args: func(proto string, ent bool) map[string]any { return makeTestWasmConfig(proto, ent).toMap(t) }, }, } for _, enterprise := range []bool{false, true} { for _, protocol := range []string{"tcp", "http"} { for name, c := range cases { c := c t.Run(fmt.Sprintf("%s_%s_ent_%t", name, protocol, enterprise), func(t *testing.T) { svc := api.CompoundServiceName{Name: "svc"} ext := extensioncommon.RuntimeConfig{ ServiceName: svc, EnvoyExtension: api.EnvoyExtension{ Name: c.name, Arguments: c.args(protocol, enterprise), }, } e, err := Constructor(ext.EnvoyExtension) if c.errStr == "" { require.NoError(t, err) require.NotNil(t, e) } else { require.Error(t, err) require.Contains(t, err.Error(), c.errStr) } }) } } } } type testWasmConfig struct { Required bool Protocol string ProxyType string ListenerType string PluginConfig struct { Name string RootID string VmConfig struct { VmID string Runtime string Code struct { Local struct { Filename string } Remote struct { HttpURI struct { Service api.CompoundServiceName URI string Timeout string } SHA256 string RetryPolicy struct { RetryBackOff struct { BaseInterval string MaxInterval string } NumRetries int } } } Configuration string EnvironmentVariables struct { HostEnvKeys []string KeyValues map[string]string } } Configuration string CapabilityRestrictionConfiguration struct { AllowedCapabilities map[string]any } } } func (c testWasmConfig) toMap(t *testing.T) map[string]any { t.Helper() var m map[string]any require.NoError(t, json.Unmarshal(c.toJSON(t), &m)) return m } func (c testWasmConfig) toJSON(t *testing.T) []byte { t.Helper() b, err := json.MarshalIndent(c, "", " ") require.NoError(t, err) return b } func (cfg testWasmConfig) toWasmPluginConfig(t *testing.T) *envoy_wasm_v3.PluginConfig { t.Helper() var code *envoy_core_v3.AsyncDataSource if cfg.PluginConfig.VmConfig.Code.Local.Filename != "" { code = &envoy_core_v3.AsyncDataSource{ Specifier: &envoy_core_v3.AsyncDataSource_Local{ Local: &envoy_core_v3.DataSource{ Specifier: &envoy_core_v3.DataSource_Filename{ Filename: cfg.PluginConfig.VmConfig.Code.Local.Filename, }, }, }, } } else { cluster, err := url.Parse(cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.URI) require.NoError(t, err) timeout, err := time.ParseDuration(cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Timeout) require.NoError(t, err) baseInterval, err := time.ParseDuration(cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.BaseInterval) require.NoError(t, err) maxInterval, err := time.ParseDuration(cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.MaxInterval) require.NoError(t, err) code = &envoy_core_v3.AsyncDataSource{ Specifier: &envoy_core_v3.AsyncDataSource_Remote{ Remote: &envoy_core_v3.RemoteDataSource{ Sha256: cfg.PluginConfig.VmConfig.Code.Remote.SHA256, HttpUri: &envoy_core_v3.HttpUri{ Uri: cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.URI, Timeout: &durationpb.Duration{Seconds: int64(timeout.Seconds())}, HttpUpstreamType: &envoy_core_v3.HttpUri_Cluster{ Cluster: cluster.Host, }, }, RetryPolicy: &envoy_core_v3.RetryPolicy{ RetryBackOff: &envoy_core_v3.BackoffStrategy{ BaseInterval: &durationpb.Duration{Seconds: int64(baseInterval.Seconds())}, MaxInterval: &durationpb.Duration{Seconds: int64(maxInterval.Seconds())}, }, NumRetries: wrapperspb.UInt32(uint32(cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.NumRetries)), }, }, }, } } var capConfig *envoy_wasm_v3.CapabilityRestrictionConfig if len(cfg.PluginConfig.CapabilityRestrictionConfiguration.AllowedCapabilities) > 0 { caps := make(map[string]*envoy_wasm_v3.SanitizationConfig) for cap := range cfg.PluginConfig.CapabilityRestrictionConfiguration.AllowedCapabilities { caps[cap] = &envoy_wasm_v3.SanitizationConfig{} } capConfig = &envoy_wasm_v3.CapabilityRestrictionConfig{AllowedCapabilities: caps} } var vmConfiguration *anypb.Any if cfg.PluginConfig.VmConfig.Configuration != "" { vmConfiguration = makeAny(t, wrapperspb.String(cfg.PluginConfig.VmConfig.Configuration)) } var envVars *envoy_wasm_v3.EnvironmentVariables if len(cfg.PluginConfig.VmConfig.EnvironmentVariables.HostEnvKeys) > 0 || len(cfg.PluginConfig.VmConfig.EnvironmentVariables.KeyValues) > 0 { envVars = &envoy_wasm_v3.EnvironmentVariables{ HostEnvKeys: cfg.PluginConfig.VmConfig.EnvironmentVariables.HostEnvKeys, KeyValues: cfg.PluginConfig.VmConfig.EnvironmentVariables.KeyValues, } } var pluginConfiguration *anypb.Any if cfg.PluginConfig.Configuration != "" { pluginConfiguration = makeAny(t, wrapperspb.String(cfg.PluginConfig.Configuration)) } rt := cfg.PluginConfig.VmConfig.Runtime if rt == "" { rt = supportedRuntimes[0] } return &envoy_wasm_v3.PluginConfig{ Name: cfg.PluginConfig.Name, RootId: cfg.PluginConfig.RootID, Vm: &envoy_wasm_v3.PluginConfig_VmConfig{ VmConfig: &envoy_wasm_v3.VmConfig{ VmId: cfg.PluginConfig.VmConfig.VmID, Runtime: fmt.Sprintf("envoy.wasm.runtime.%s", rt), Code: code, Configuration: vmConfiguration, EnvironmentVariables: envVars, }, }, Configuration: pluginConfiguration, FailOpen: !cfg.Required, CapabilityRestrictionConfig: capConfig, } } func (cfg testWasmConfig) toHttpFilter(t *testing.T) *envoy_http_v3.HttpFilter { return &envoy_http_v3.HttpFilter{ Name: "envoy.filters.http.wasm", ConfigType: &envoy_http_v3.HttpFilter_TypedConfig{ TypedConfig: makeAny(t, &envoy_http_wasm_v3.Wasm{ Config: cfg.toWasmPluginConfig(t), }), }, } } func (cfg testWasmConfig) toNetworkFilter(t *testing.T) *envoy_listener_v3.Filter { return &envoy_listener_v3.Filter{ Name: "envoy.filters.network.wasm", ConfigType: &envoy_listener_v3.Filter_TypedConfig{ TypedConfig: makeAny(t, &envoy_network_wasm_v3.Wasm{ Config: cfg.toWasmPluginConfig(t), }), }, } } func (cfg testWasmConfig) expFilters(t *testing.T) []*envoy_listener_v3.Filter { if cfg.Protocol == "http" { return []*envoy_listener_v3.Filter{makeHttpConMgr(t, cfg.expHttpFilters(t))} } else { return cfg.expNetworkFilters(t) } } func (cfg testWasmConfig) expHttpFilters(t *testing.T) []*envoy_http_v3.HttpFilter { return []*envoy_http_v3.HttpFilter{ {Name: "one"}, {Name: "two"}, cfg.toHttpFilter(t), {Name: "envoy.filters.http.router"}, {Name: "three"}, } } func (cfg testWasmConfig) expNetworkFilters(t *testing.T) []*envoy_listener_v3.Filter { return []*envoy_listener_v3.Filter{ {Name: "one"}, {Name: "two"}, cfg.toNetworkFilter(t), {Name: "envoy.filters.network.tcp_proxy"}, {Name: "three"}, } } func (cfg testWasmConfig) matchesDirection(isInbound bool) bool { return (isInbound && cfg.ListenerType == "inbound") || (!isInbound && cfg.ListenerType == "outbound") } func makeAny(t *testing.T, m proto.Message) *anypb.Any { t.Helper() v, err := anypb.New(m) require.NoError(t, err) return v } func makeHttpConMgr(t *testing.T, filters []*envoy_http_v3.HttpFilter) *envoy_listener_v3.Filter { t.Helper() return &envoy_listener_v3.Filter{ Name: "envoy.filters.network.http_connection_manager", ConfigType: &envoy_listener_v3.Filter_TypedConfig{ TypedConfig: makeAny(t, &envoy_http_v3.HttpConnectionManager{ HttpFilters: filters, }), }, } } func makeTestFilters() []*envoy_listener_v3.Filter { return []*envoy_listener_v3.Filter{ {Name: "one"}, {Name: "two"}, {Name: "envoy.filters.network.tcp_proxy"}, {Name: "three"}, } } func makeTestHttpFilters() []*envoy_http_v3.HttpFilter { return []*envoy_http_v3.HttpFilter{ {Name: "one"}, {Name: "two"}, {Name: "envoy.filters.http.router"}, {Name: "three"}, } } func makeTestRuntimeConfig(protocol string, enterprise bool) *extensioncommon.RuntimeConfig { var ns, ap string if enterprise { ns = "ns1" ap = "ap1" } return &extensioncommon.RuntimeConfig{ Kind: api.ServiceKindConnectProxy, ServiceName: api.CompoundServiceName{Name: "test-service"}, Upstreams: map[api.CompoundServiceName]*extensioncommon.UpstreamData{ { Name: "test-file-server", Namespace: acl.NamespaceOrDefault(ns), Partition: acl.PartitionOrDefault(ap), }: { SNIs: map[string]struct{}{"test-file-server": {}}, EnvoyID: "test-file-server", }, }, Protocol: protocol, } } func makeTestWasmConfig(protocol string, enterprise bool) *testWasmConfig { cfg := newTestWasmConfig(protocol, enterprise) cfg.Required = false cfg.Protocol = protocol cfg.ProxyType = "connect-proxy" cfg.ListenerType = "inbound" cfg.PluginConfig.Name = "test-plugin-name" cfg.PluginConfig.RootID = "test-root-id" cfg.PluginConfig.VmConfig.VmID = "test-vm-id" cfg.PluginConfig.VmConfig.Runtime = "wasmtime" cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Service.Name = "test-file-server" cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.URI = "https://test-file-server/plugin.wasm" cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Timeout = "5s" cfg.PluginConfig.VmConfig.Code.Remote.SHA256 = "d05d88b0ce8a8f1d5176481e0af3ae5c65ed82cbfb8c61506c5354b076078545" cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.BaseInterval = "3s" cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.RetryBackOff.MaxInterval = "15s" cfg.PluginConfig.VmConfig.Code.Remote.RetryPolicy.NumRetries = 3 cfg.PluginConfig.VmConfig.Configuration = "test-vm-configuration" cfg.PluginConfig.VmConfig.EnvironmentVariables.HostEnvKeys = []string{"PATH"} cfg.PluginConfig.VmConfig.EnvironmentVariables.KeyValues = map[string]string{"TEST_VAR": "TEST_VAL"} cfg.PluginConfig.Configuration = "test-plugin-configuration" cfg.PluginConfig.CapabilityRestrictionConfiguration.AllowedCapabilities = map[string]any{"proxy_on_vm_start": true} return cfg } func newTestWasmConfig(protocol string, enterprise bool) *testWasmConfig { cfg := &testWasmConfig{Protocol: protocol} if enterprise { cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Service.Namespace = "ns1" cfg.PluginConfig.VmConfig.Code.Remote.HttpURI.Service.Partition = "ap1" } return cfg } func protoToJSON(t *testing.T, pb proto.Message) string { t.Helper() m := protojson.MarshalOptions{ Indent: " ", } gotJSON, err := m.Marshal(pb) require.NoError(t, err) return string(gotJSON) } func setField(m map[string]any, path string, value any) { upsertField(m, path, value, 0) } func upsertField(m map[string]any, path string, value any, index int) { keys := strings.Split(path, ".") key := keys[index] if val, ok := m[key]; ok { // update the value if index == len(keys)-1 { m[key] = value } else { upsertField(val.(map[string]any), path, value, index+1) } } else { // key does not exist so insert it if index == len(keys)-1 { m[key] = value } else { newMap := make(map[string]any) m[key] = newMap upsertField(newMap, path, value, index+1) } } }