conditionally write generated files (#890)

Taskfile.yml

@@ -189,20 +189,8 @@ tasks:
         sources:
             - "cmd/generatego/*.go"
             - "cmd/generatets/*.go"
-            - "pkg/service/**/*.go"
-            - "pkg/waveobj/*.go"
-            - "pkg/wconfig/**/*.go"
-            - "pkg/wstore/*.go"
-            - "pkg/wshrpc/**/*.go"
-            - "pkg/tsgen/**/*.go"
-            - "pkg/gogen/**/*.go"
-            - "pkg/wconfig/**/*.go"
-            - "pkg/eventbus/eventbus.go"
-        generates:
-            - frontend/types/gotypes.d.ts
-            - pkg/wshrpc/wshclient/wshclient.go
-            - frontend/app/store/services.ts
-            - frontend/app/store/wshserver.ts
+            - "pkg/**/*.go"
+        # don't add generates key (otherwise will always execute)
 
     version:
         desc: Get the current package version, or bump version if args are present. To pass args to `version.cjs`, add them after `--`. See `version.cjs` for usage definitions for the arguments.

cmd/generatego/main-generatego.go

@@ -20,7 +20,7 @@ const WshClientFileName = "pkg/wshrpc/wshclient/wshclient.go"
 const WaveObjMetaConstsFileName = "pkg/waveobj/metaconsts.go"
 const SettingsMetaConstsFileName = "pkg/wconfig/metaconsts.go"
 
-func GenerateWshClient() {
+func GenerateWshClient() error {
 	fmt.Fprintf(os.Stderr, "generating wshclient file to %s\n", WshClientFileName)
 	var buf strings.Builder
 	gogen.GenerateBoilerplate(&buf, "wshclient", []string{
@@ -42,38 +42,53 @@ func GenerateWshClient() {
 		}
 	}
 	buf.WriteString("\n")
-	err := os.WriteFile(WshClientFileName, []byte(buf.String()), 0644)
-	if err != nil {
-		panic(err)
+	written, err := utilfn.WriteFileIfDifferent(WshClientFileName, []byte(buf.String()))
+	if !written {
+		fmt.Fprintf(os.Stderr, "no changes to %s\n", WshClientFileName)
 	}
+	return err
 }
 
-func GenerateWaveObjMetaConsts() {
+func GenerateWaveObjMetaConsts() error {
 	fmt.Fprintf(os.Stderr, "generating waveobj meta consts file to %s\n", WaveObjMetaConstsFileName)
 	var buf strings.Builder
 	gogen.GenerateBoilerplate(&buf, "waveobj", []string{})
 	gogen.GenerateMetaMapConsts(&buf, "MetaKey_", reflect.TypeOf(waveobj.MetaTSType{}))
 	buf.WriteString("\n")
-	err := os.WriteFile(WaveObjMetaConstsFileName, []byte(buf.String()), 0644)
-	if err != nil {
-		panic(err)
+	written, err := utilfn.WriteFileIfDifferent(WaveObjMetaConstsFileName, []byte(buf.String()))
+	if !written {
+		fmt.Fprintf(os.Stderr, "no changes to %s\n", WaveObjMetaConstsFileName)
 	}
+	return err
 }
 
-func GenerateSettingsMetaConsts() {
+func GenerateSettingsMetaConsts() error {
 	fmt.Fprintf(os.Stderr, "generating settings meta consts file to %s\n", SettingsMetaConstsFileName)
 	var buf strings.Builder
 	gogen.GenerateBoilerplate(&buf, "wconfig", []string{})
 	gogen.GenerateMetaMapConsts(&buf, "ConfigKey_", reflect.TypeOf(wconfig.SettingsType{}))
 	buf.WriteString("\n")
-	err := os.WriteFile(SettingsMetaConstsFileName, []byte(buf.String()), 0644)
-	if err != nil {
-		panic(err)
+	written, err := utilfn.WriteFileIfDifferent(SettingsMetaConstsFileName, []byte(buf.String()))
+	if !written {
+		fmt.Fprintf(os.Stderr, "no changes to %s\n", SettingsMetaConstsFileName)
 	}
+	return err
 }
 
 func main() {
-	GenerateWshClient()
-	GenerateWaveObjMetaConsts()
-	GenerateSettingsMetaConsts()
+	err := GenerateWshClient()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error generating wshclient: %v\n", err)
+		return
+	}
+	err = GenerateWaveObjMetaConsts()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error generating waveobj meta consts: %v\n", err)
+		return
+	}
+	err = GenerateSettingsMetaConsts()
+	if err != nil {
+		fmt.Fprintf(os.Stderr, "error generating settings meta consts: %v\n", err)
+		return
+	}
 }

cmd/generatets/main-generatets.go

@@ -4,6 +4,7 @@
 package main
 
 import (
+	"bytes"
 	"fmt"
 	"os"
 	"reflect"
@@ -17,14 +18,10 @@ import (
 )
 
 func generateTypesFile(tsTypesMap map[reflect.Type]string) error {
-	fd, err := os.Create("frontend/types/gotypes.d.ts")
-	if err != nil {
-		return err
-	}
-	defer fd.Close()
-	fmt.Fprintf(os.Stderr, "generating types file to %s\n", fd.Name())
+	fileName := "frontend/types/gotypes.d.ts"
+	fmt.Fprintf(os.Stderr, "generating types file to %s\n", fileName)
 	tsgen.GenerateWaveObjTypes(tsTypesMap)
-	err = tsgen.GenerateServiceTypes(tsTypesMap)
+	err := tsgen.GenerateServiceTypes(tsTypesMap)
 	if err != nil {
 		fmt.Fprintf(os.Stderr, "Error generating service types: %v\n", err)
 		os.Exit(1)
@@ -33,10 +30,11 @@ func generateTypesFile(tsTypesMap map[reflect.Type]string) error {
 	if err != nil {
 		return fmt.Errorf("error generating wsh server types: %w", err)
 	}
-	fmt.Fprintf(fd, "// Copyright 2024, Command Line Inc.\n")
-	fmt.Fprintf(fd, "// SPDX-License-Identifier: Apache-2.0\n\n")
-	fmt.Fprintf(fd, "// generated by cmd/generate/main-generatets.go\n\n")
-	fmt.Fprintf(fd, "declare global {\n\n")
+	var buf bytes.Buffer
+	fmt.Fprintf(&buf, "// Copyright 2024, Command Line Inc.\n")
+	fmt.Fprintf(&buf, "// SPDX-License-Identifier: Apache-2.0\n\n")
+	fmt.Fprintf(&buf, "// generated by cmd/generate/main-generatets.go\n\n")
+	fmt.Fprintf(&buf, "declare global {\n\n")
 	var keys []reflect.Type
 	for key := range tsTypesMap {
 		keys = append(keys, key)
@@ -48,63 +46,69 @@ func generateTypesFile(tsTypesMap map[reflect.Type]string) error {
 	})
 	for _, key := range keys {
 		// don't output generic types
-		if strings.Index(key.Name(), "[") != -1 {
+		if strings.Contains(key.Name(), "[") {
 			continue
 		}
 		tsCode := tsTypesMap[key]
 		istr := utilfn.IndentString("    ", tsCode)
-		fmt.Fprint(fd, istr)
+		fmt.Fprint(&buf, istr)
 	}
-	fmt.Fprintf(fd, "}\n\n")
-	fmt.Fprintf(fd, "export {}\n")
-	return nil
+	fmt.Fprintf(&buf, "}\n\n")
+	fmt.Fprintf(&buf, "export {}\n")
+	written, err := utilfn.WriteFileIfDifferent(fileName, buf.Bytes())
+	if !written {
+		fmt.Fprintf(os.Stderr, "no changes to %s\n", fileName)
+	}
+	return err
 }
 
 func generateServicesFile(tsTypesMap map[reflect.Type]string) error {
-	fd, err := os.Create("frontend/app/store/services.ts")
-	if err != nil {
-		return err
-	}
-	defer fd.Close()
-	fmt.Fprintf(os.Stderr, "generating services file to %s\n", fd.Name())
-	fmt.Fprintf(fd, "// Copyright 2024, Command Line Inc.\n")
-	fmt.Fprintf(fd, "// SPDX-License-Identifier: Apache-2.0\n\n")
-	fmt.Fprintf(fd, "// generated by cmd/generate/main-generatets.go\n\n")
-	fmt.Fprintf(fd, "import * as WOS from \"./wos\";\n\n")
+	fileName := "frontend/app/store/services.ts"
+	var buf bytes.Buffer
+	fmt.Fprintf(os.Stderr, "generating services file to %s\n", fileName)
+	fmt.Fprintf(&buf, "// Copyright 2024, Command Line Inc.\n")
+	fmt.Fprintf(&buf, "// SPDX-License-Identifier: Apache-2.0\n\n")
+	fmt.Fprintf(&buf, "// generated by cmd/generate/main-generatets.go\n\n")
+	fmt.Fprintf(&buf, "import * as WOS from \"./wos\";\n\n")
 	orderedKeys := utilfn.GetOrderedMapKeys(service.ServiceMap)
 	for _, serviceName := range orderedKeys {
 		serviceObj := service.ServiceMap[serviceName]
 		svcStr := tsgen.GenerateServiceClass(serviceName, serviceObj, tsTypesMap)
-		fmt.Fprint(fd, svcStr)
-		fmt.Fprint(fd, "\n")
+		fmt.Fprint(&buf, svcStr)
+		fmt.Fprint(&buf, "\n")
 	}
-	return nil
+	written, err := utilfn.WriteFileIfDifferent(fileName, buf.Bytes())
+	if !written {
+		fmt.Fprintf(os.Stderr, "no changes to %s\n", fileName)
+	}
+	return err
 }
 
 func generateWshClientApiFile(tsTypeMap map[reflect.Type]string) error {
-	fd, err := os.Create("frontend/app/store/wshclientapi.ts")
-	if err != nil {
-		return err
-	}
-	defer fd.Close()
+	fileName := "frontend/app/store/wshclientapi.ts"
+	var buf bytes.Buffer
 	declMap := wshrpc.GenerateWshCommandDeclMap()
-	fmt.Fprintf(os.Stderr, "generating wshclientapi file to %s\n", fd.Name())
-	fmt.Fprintf(fd, "// Copyright 2024, Command Line Inc.\n")
-	fmt.Fprintf(fd, "// SPDX-License-Identifier: Apache-2.0\n\n")
-	fmt.Fprintf(fd, "// generated by cmd/generate/main-generatets.go\n\n")
-	fmt.Fprintf(fd, "import { WshClient } from \"./wshclient\";\n\n")
+	fmt.Fprintf(os.Stderr, "generating wshclientapi file to %s\n", fileName)
+	fmt.Fprintf(&buf, "// Copyright 2024, Command Line Inc.\n")
+	fmt.Fprintf(&buf, "// SPDX-License-Identifier: Apache-2.0\n\n")
+	fmt.Fprintf(&buf, "// generated by cmd/generate/main-generatets.go\n\n")
+	fmt.Fprintf(&buf, "import { WshClient } from \"./wshclient\";\n\n")
 	orderedKeys := utilfn.GetOrderedMapKeys(declMap)
-	fmt.Fprintf(fd, "// WshServerCommandToDeclMap\n")
-	fmt.Fprintf(fd, "class RpcApiType {\n")
+	fmt.Fprintf(&buf, "// WshServerCommandToDeclMap\n")
+	fmt.Fprintf(&buf, "class RpcApiType {\n")
 	for _, methodDecl := range orderedKeys {
 		methodDecl := declMap[methodDecl]
 		methodStr := tsgen.GenerateWshClientApiMethod(methodDecl, tsTypeMap)
-		fmt.Fprint(fd, methodStr)
-		fmt.Fprintf(fd, "\n")
+		fmt.Fprint(&buf, methodStr)
+		fmt.Fprintf(&buf, "\n")
 	}
-	fmt.Fprintf(fd, "}\n\n")
-	fmt.Fprintf(fd, "export const RpcApi = new RpcApiType();\n")
-	return nil
+	fmt.Fprintf(&buf, "}\n\n")
+	fmt.Fprintf(&buf, "export const RpcApi = new RpcApiType();\n")
+	written, err := utilfn.WriteFileIfDifferent(fileName, buf.Bytes())
+	if !written {
+		fmt.Fprintf(os.Stderr, "no changes to %s\n", fileName)
+	}
+	return err
 }
 
 func main() {

pkg/util/utilfn/utilfn.go

@@ -920,3 +920,15 @@ func GetJsonTag(field reflect.StructField) string {
 	}
 	return jsonTag
 }
+
+func WriteFileIfDifferent(fileName string, contents []byte) (bool, error) {
+	oldContents, err := os.ReadFile(fileName)
+	if err == nil && bytes.Equal(oldContents, contents) {
+		return false, nil
+	}
+	err = os.WriteFile(fileName, contents, 0644)
+	if err != nil {
+		return false, err
+	}
+	return true, nil
+}