[all] Add leading slash in path if missing

Author: jmini

Diff for: modules/openapi-generator/src/main/java/org/openapitools/codegen/DefaultCodegen.java

@@ -2254,7 +2254,11 @@ public CodegenOperation fromOperation(String path,
         }
         operationId = removeNonNameElementToCamelCase(operationId);
 
-        op.path = path;
+        if(path.startsWith("/")) {
+            op.path = path;
+        } else {
+            op.path = "/" + path;
+        }
         op.operationId = toOperationId(operationId);
         op.summary = escapeText(operation.getSummary());
         op.unescapedNotes = operation.getDescription();

Diff for: modules/openapi-generator/src/test/java/org/openapitools/codegen/DefaultCodegenTest.java

@@ -21,6 +21,7 @@
 import io.swagger.v3.oas.models.Components;
 import io.swagger.v3.oas.models.OpenAPI;
 import io.swagger.v3.oas.models.Operation;
+import io.swagger.v3.oas.models.PathItem;
 import io.swagger.v3.oas.models.media.ArraySchema;
 import io.swagger.v3.oas.models.media.Content;
 import io.swagger.v3.oas.models.media.MediaType;
@@ -37,7 +38,6 @@
 import org.testng.Assert;
 import org.testng.annotations.Test;
 
-import java.lang.reflect.Method;
 import java.util.*;
 import java.util.stream.Collectors;
 
@@ -500,6 +500,21 @@ public void testCallbacks() {
         });
     }
 
+    @Test
+    public void testLeadingSlashIsAddedIfMissing() {
+        OpenAPI openAPI = TestUtils.createOpenAPI();
+        Operation operation1 = new Operation().operationId("op1").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")));
+        openAPI.path("/here", new PathItem().get(operation1));
+        Operation operation2 = new Operation().operationId("op2").responses(new ApiResponses().addApiResponse("201", new ApiResponse().description("OK")));
+        openAPI.path("some/path", new PathItem().get(operation2));
+        final DefaultCodegen codegen = new DefaultCodegen();
+
+        CodegenOperation co1 = codegen.fromOperation("/here", "get", operation2, ModelUtils.getSchemas(openAPI), openAPI);
+        Assert.assertEquals(co1.path, "/here");
+        CodegenOperation co2 = codegen.fromOperation("some/path", "get", operation2, ModelUtils.getSchemas(openAPI), openAPI);
+        Assert.assertEquals(co2.path, "/some/path");
+    }
+
     private void verifyPersonDiscriminator(CodegenDiscriminator discriminator) {
         CodegenDiscriminator test = new CodegenDiscriminator();
         test.setPropertyName("$_type");