Generate API files as interfaces for go-gin server (OpenAPITools#17784)

* add feature to generate only interface files

* generate sample

* add workflow file foe go gin service

* add workflow file foe go gin service

* add workflow file foe go gin service

* update samples

Author: mfatihercik

.github/workflows/samples-go-gin.yaml

@@ -0,0 +1,31 @@
+name: Samples Go 
+
+on:
+  push:
+    paths:
+      - 'samples/server/petstore/go-gin-api-server/**'
+      - 'samples/server/petstore/go-gin-api-server-interface-only/**'
+  pull_request:
+    paths:
+      - 'samples/server/petstore/go-gin-api-server/**'
+      - 'samples/server/petstore/go-gin-api-server-interface-only/**'
+
+jobs:
+  build:
+    name: Build Go 
+    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        sample:
+          - samples/server/petstore/go-gin-api-server/
+          - samples/server/petstore/go-gin-api-server-interface-only/
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-go@v5
+        with:
+          go-version: "stable"
+      - run: go version
+      - name: Run test
+        working-directory: ${{ matrix.sample }}
+        run: go test -mod=mod -v

bin/configs/go-gin-server-go-gin-api-server-interface-only.yaml

@@ -0,0 +1,8 @@
+generatorName: go-gin-server
+outputDir: samples/server/petstore/go-gin-api-server-interface-only
+inputSpec: modules/openapi-generator/src/test/resources/3_0/petstore.yaml
+templateDir: modules/openapi-generator/src/main/resources/go-gin-server
+additionalProperties:
+  hideGenerationTimestamp: "true"
+  packageName: petstoreserver
+  interfaceOnly: true

docs/generators/go-gin-server.md

@@ -21,6 +21,7 @@ These options may be applied as additional-properties (cli) or configOptions (pl
 |apiPath|Name of the folder that contains the Go source code| |go|
 |enumClassPrefix|Prefix enum with class name| |false|
 |hideGenerationTimestamp|Hides the generation timestamp when files are generated.| |true|
+|interfaceOnly|Whether to generate only API interface stubs without the implementation files.| |false|
 |packageName|Go package name (convention: lowercase).| |openapi|
 |packageVersion|Go package version.| |1.0.0|
 |serverPort|The network port the generated server binds to| |8080|

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/GoGinServerCodegen.java

@@ -38,6 +38,10 @@ public class GoGinServerCodegen extends AbstractGoCodegen {
 
     private final Logger LOGGER = LoggerFactory.getLogger(GoGinServerCodegen.class);
 
+    public static final String INTERFACE_ONLY = "interfaceOnly";
+
+    protected boolean interfaceOnly = false;
+
     protected String apiVersion = "1.0.0";
     protected int serverPort = 8080;
     protected String projectName = "openapi-server";
@@ -114,6 +118,8 @@ public GoGinServerCodegen() {
 
         cliOptions.add(new CliOption("apiPath", "Name of the folder that contains the Go source code")
                 .defaultValue(apiPath));
+        cliOptions.add(CliOption.newBoolean(INTERFACE_ONLY,
+                "Whether to generate only API interface stubs without the implementation files.", interfaceOnly));
 
         CliOption optServerPort = new CliOption("serverPort", "The network port the generated server binds to");
         optServerPort.setType("int");
@@ -148,6 +154,10 @@ public void processOpts() {
             additionalProperties.put(CodegenConstants.PACKAGE_NAME, this.packageName);
         }
 
+        if (additionalProperties.containsKey(INTERFACE_ONLY)) {
+            this.setInterfaceOnly(Boolean.parseBoolean(additionalProperties.get(INTERFACE_ONLY).toString()));
+        }
+
         /*
          * Additional Properties.  These values can be passed to the templates and
          * are available in models, apis, and supporting files
@@ -180,6 +190,11 @@ public void processOpts() {
         modelPackage = packageName;
         apiPackage = packageName;
 
+        if (interfaceOnly) {
+            apiTemplateFiles.clear();
+            apiTemplateFiles.put("interface-api.mustache", ".go");
+        }
+
         /*
          * Supporting Files.  You can write single files for the generator with the
          * entire object tree available.  If the input file has a suffix of `.mustache
@@ -194,6 +209,10 @@ public void processOpts() {
         supportingFiles.add(new SupportingFile("go.mod.mustache", "go.mod"));
     }
 
+    public void setInterfaceOnly(boolean interfaceOnly) {
+        this.interfaceOnly = interfaceOnly;
+    }
+
     @Override
     public String apiPackage() {
         return apiPath;

modules/openapi-generator/src/main/resources/go-gin-server/interface-api.mustache

@@ -0,0 +1,22 @@
+{{>partial_header}}
+package {{packageName}}
+
+{{#operations}}
+import (
+	"github.com/gin-gonic/gin"
+)
+
+type {{classname}} interface {
+
+
+    {{#operation}}
+    // {{nickname}} {{httpMethod}} {{{basePathWithoutHost}}}{{{path}}}{{#summary}}
+    // {{{.}}} {{/summary}}
+    {{#isDeprecated}}
+    // Deprecated
+    {{/isDeprecated}}
+     {{nickname}}(c *gin.Context)
+
+    {{/operation}}
+    {{/operations}}
+}

modules/openapi-generator/src/test/java/org/openapitools/codegen/goginserver/GoGinServerCodegenTest.java

@@ -17,20 +17,16 @@
 
 package org.openapitools.codegen.goginserver;
 
-import org.openapitools.codegen.*;
+import org.openapitools.codegen.DefaultGenerator;
+import org.openapitools.codegen.TestUtils;
 import org.openapitools.codegen.config.CodegenConfigurator;
-import org.openapitools.codegen.languages.GoClientCodegen;
-import org.testng.Assert;
 import org.testng.annotations.Test;
 
 import java.io.File;
 import java.io.IOException;
 import java.nio.file.Files;
-import java.nio.file.Path;
 import java.nio.file.Paths;
-import java.util.HashMap;
 import java.util.List;
-import java.util.Map;
 
 
 public class GoGinServerCodegenTest {
@@ -40,13 +36,8 @@ public void verifyGoMod() throws IOException {
         File output = Files.createTempDirectory("test").toFile();
         output.deleteOnExit();
 
-        final CodegenConfigurator configurator = new CodegenConfigurator()
-                .setGeneratorName("go-gin-server")
-                .setGitUserId("my-user")
-                .setGitRepoId("my-repo")
-                .setPackageName("my-package")
-                .setInputSpec("src/test/resources/3_0/petstore.yaml")
-                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+        final CodegenConfigurator configurator = createDefaultCodegenConfigurator(output)
+                .setInputSpec("src/test/resources/3_0/petstore.yaml");
 
         DefaultGenerator generator = new DefaultGenerator();
         List<File> files = generator.opts(configurator.toClientOptInput()).generate();
@@ -64,13 +55,8 @@ public void webhooks() throws IOException {
         File output = Files.createTempDirectory("test").toFile();
         output.deleteOnExit();
 
-        final CodegenConfigurator configurator = new CodegenConfigurator()
-                .setGeneratorName("go-gin-server")
-                .setGitUserId("my-user")
-                .setGitRepoId("my-repo")
-                .setPackageName("my-package")
-                .setInputSpec("src/test/resources/3_1/webhooks.yaml")
-                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+        final CodegenConfigurator configurator = createDefaultCodegenConfigurator(output)
+                .setInputSpec("src/test/resources/3_1/webhooks.yaml");
 
         DefaultGenerator generator = new DefaultGenerator();
         List<File> files = generator.opts(configurator.toClientOptInput()).generate();
@@ -82,4 +68,30 @@ public void webhooks() throws IOException {
                 " c.JSON(200, gin.H{\"status\": \"OK\"})");
     }
 
+    @Test
+    public void verifyInterfaceOnly() throws IOException {
+        File output = Files.createTempDirectory("test").toFile();
+        output.deleteOnExit();
+
+        final CodegenConfigurator configurator = createDefaultCodegenConfigurator(output)
+                .setInputSpec("src/test/resources/3_0/petstore.yaml")
+                .addAdditionalProperty("interfaceOnly", true);
+
+        DefaultGenerator generator = new DefaultGenerator();
+        List<File> files = generator.opts(configurator.toClientOptInput()).generate();
+        files.forEach(File::deleteOnExit);
+
+        TestUtils.assertFileContains(Paths.get(output + "/go/api_pet.go"),
+                "type PetAPI interface");
+    }
+
+    private static CodegenConfigurator createDefaultCodegenConfigurator(File output) {
+        return new CodegenConfigurator()
+                .setGeneratorName("go-gin-server")
+                .setGitUserId("my-user")
+                .setGitRepoId("my-repo")
+                .setPackageName("my-package")
+                .setOutputDir(output.getAbsolutePath().replace("\\", "/"));
+    }
+
 }

samples/server/petstore/go-gin-api-server-interface-only/.openapi-generator-ignore

@@ -0,0 +1,23 @@
+# OpenAPI Generator Ignore
+# Generated by openapi-generator https://github.com/openapitools/openapi-generator
+
+# Use this file to prevent files from being overwritten by the generator.
+# The patterns follow closely to .gitignore or .dockerignore.
+
+# As an example, the C# client generator defines ApiClient.cs.
+# You can make changes and tell OpenAPI Generator to ignore just this file by uncommenting the following line:
+#ApiClient.cs
+
+# You can match any string of characters against a directory, file or extension with a single asterisk (*):
+#foo/*/qux
+# The above matches foo/bar/qux and foo/baz/qux, but not foo/bar/baz/qux
+
+# You can recursively match patterns against a directory, file or extension with a double asterisk (**):
+#foo/**/qux
+# This matches foo/bar/qux, foo/baz/qux, and foo/bar/baz/qux
+
+# You can also negate patterns with an exclamation (!).
+# For example, you can ignore all files in a docs folder with the file extension .md:
+#docs/*.md
+# Then explicitly reverse the ignore rule for a single file:
+#!docs/README.md

samples/server/petstore/go-gin-api-server-interface-only/.openapi-generator/FILES

@@ -0,0 +1,15 @@
+Dockerfile
+api/openapi.yaml
+go.mod
+go/README.md
+go/api_pet.go
+go/api_store.go
+go/api_user.go
+go/model_api_response.go
+go/model_category.go
+go/model_order.go
+go/model_pet.go
+go/model_tag.go
+go/model_user.go
+go/routers.go
+main.go

samples/server/petstore/go-gin-api-server-interface-only/.openapi-generator/VERSION

@@ -0,0 +1 @@
+7.4.0-SNAPSHOT

samples/server/petstore/go-gin-api-server-interface-only/Dockerfile

@@ -0,0 +1,16 @@
+FROM golang:1.19 AS build
+WORKDIR /go/src
+COPY go ./go
+COPY main.go .
+COPY go.sum .
+COPY go.mod .
+
+ENV CGO_ENABLED=0
+
+RUN go build -o petstoreserver .
+
+FROM scratch AS runtime
+ENV GIN_MODE=release
+COPY --from=build /go/src/petstoreserver ./
+EXPOSE 8080/tcp
+ENTRYPOINT ["./petstoreserver"]