Add sanitization logic for generated flatten schema names

openapi-cli/src/main/java/io/ballerina/openapi/cmd/Flatten.java

@@ -18,12 +18,15 @@
 package io.ballerina.openapi.cmd;
 
 import io.ballerina.cli.BLauncherCmd;
+import io.ballerina.openapi.core.generators.common.OASModifier;
 import io.ballerina.openapi.core.generators.common.model.Filter;
 import io.ballerina.openapi.service.mapper.utils.CodegenUtils;
 import io.swagger.parser.OpenAPIParser;
 import io.swagger.v3.core.util.Json;
 import io.swagger.v3.core.util.Yaml;
+import io.swagger.v3.oas.models.Components;
 import io.swagger.v3.oas.models.OpenAPI;
+import io.swagger.v3.oas.models.media.Schema;
 import io.swagger.v3.parser.core.models.ParseOptions;
 import io.swagger.v3.parser.core.models.SwaggerParseResult;
 import io.swagger.v3.parser.util.InlineModelResolver;
@@ -36,7 +39,10 @@
 import java.nio.file.Paths;
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.Collections;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Objects;
 import java.util.Optional;
 
@@ -45,6 +51,8 @@
 import static io.ballerina.openapi.cmd.CmdConstants.YAML_EXTENSION;
 import static io.ballerina.openapi.cmd.CmdConstants.YML_EXTENSION;
 import static io.ballerina.openapi.core.generators.common.GeneratorConstants.UNSUPPORTED_OPENAPI_VERSION_PARSER_MESSAGE;
+import static io.ballerina.openapi.core.generators.common.OASModifier.getResolvedNameMapping;
+import static io.ballerina.openapi.core.generators.common.OASModifier.getValidNameForType;
 import static io.ballerina.openapi.service.mapper.utils.CodegenUtils.resolveContractFileName;
 
 /**
@@ -79,6 +87,8 @@ public class Flatten implements BLauncherCmd {
     private static final String FOUND_PARSER_DIAGNOSTICS = "found the following parser diagnostic messages:";
     private static final String ERROR_OCCURRED_WHILE_WRITING_THE_OUTPUT_OPENAPI_FILE = "[ERROR] error occurred while " +
             "writing the flattened OpenAPI definition file";
+    private static final String ERROR_OCCURRED_WHILE_GENERATING_SCHEMA_NAMES = "[ERROR] error occurred while " +
+            "generating schema names";
 
     private final PrintStream infoStream = System.out;
     private final PrintStream errorStream = System.err;
@@ -176,29 +186,35 @@ private void generateFlattenOpenAPI() {
     private Optional<OpenAPI> getFlattenOpenAPI(String openAPIFileContent) {
         // Read the contents of the file with default parser options
         // Flattening will be done after filtering the operations
-        SwaggerParseResult parseResult = new OpenAPIParser().readContents(openAPIFileContent, null,
+        SwaggerParseResult parserResult = new OpenAPIParser().readContents(openAPIFileContent, null,
                 new ParseOptions());
-        if (!parseResult.getMessages().isEmpty() &&
-                parseResult.getMessages().contains(UNSUPPORTED_OPENAPI_VERSION_PARSER_MESSAGE)) {
+        if (!parserResult.getMessages().isEmpty() &&
+                parserResult.getMessages().contains(UNSUPPORTED_OPENAPI_VERSION_PARSER_MESSAGE)) {
             errorStream.println(ERROR_UNSUPPORTED_OPENAPI_VERSION);
             return Optional.empty();
         }
 
-        OpenAPI openAPI = parseResult.getOpenAPI();
+        OpenAPI openAPI = parserResult.getOpenAPI();
         if (Objects.isNull(openAPI)) {
             errorStream.println(ERROR_OCCURRED_WHILE_PARSING_THE_INPUT_OPENAPI_FILE);
-            if (!parseResult.getMessages().isEmpty()) {
+            if (!parserResult.getMessages().isEmpty()) {
                 errorStream.println(FOUND_PARSER_DIAGNOSTICS);
-                parseResult.getMessages().forEach(errorStream::println);
+                parserResult.getMessages().forEach(errorStream::println);
             }
             return Optional.empty();
         }
 
+        Components components = openAPI.getComponents();
+        List<String> existingComponentNames = Objects.nonNull(components) && Objects.nonNull(components.getSchemas()) ?
+                new ArrayList<>(components.getSchemas().keySet()) : new ArrayList<>();
+
         filterOpenAPIOperations(openAPI);
+
         // Flatten the OpenAPI definition with `flattenComposedSchemas: true` and `camelCaseFlattenNaming: true`
         InlineModelResolver inlineModelResolver = new InlineModelResolver(true, true);
         inlineModelResolver.flatten(openAPI);
-        return Optional.of(openAPI);
+
+        return sanitizeOpenAPI(openAPI, existingComponentNames);
     }
 
     private void writeFlattenOpenAPIFile(OpenAPI openAPI) {
@@ -247,6 +263,50 @@ private void filterOpenAPIOperations(OpenAPI openAPI) {
         pathsToRemove.forEach(openAPI.getPaths()::remove);
     }
 
+    private Optional<OpenAPI> sanitizeOpenAPI(OpenAPI openAPI, List<String> existingComponentNames) {
+        Map<String, String> proposedNameMapping = getProposedNameMapping(openAPI, existingComponentNames);
+        if (proposedNameMapping.isEmpty()) {
+            return Optional.of(openAPI);
+        }
+
+        SwaggerParseResult parserResult = OASModifier.getOASWithSchemaNameModification(openAPI, proposedNameMapping);
+        openAPI = parserResult.getOpenAPI();
+        if (Objects.isNull(openAPI)) {
+            errorStream.println(ERROR_OCCURRED_WHILE_GENERATING_SCHEMA_NAMES);
+            if (!parserResult.getMessages().isEmpty()) {
+                errorStream.println(FOUND_PARSER_DIAGNOSTICS);
+                parserResult.getMessages().forEach(errorStream::println);
+            }
+            return Optional.empty();
+        }
+
+        return Optional.of(openAPI);
+    }
+
+    public Map<String, String> getProposedNameMapping(OpenAPI openapi, List<String> existingComponentNames) {
+        Map<String, String> nameMap = new HashMap<>();
+        if (Objects.isNull(openapi.getComponents())) {
+            return Collections.emptyMap();
+        }
+        Components components = openapi.getComponents();
+        Map<String, Schema> schemas = components.getSchemas();
+        if (Objects.isNull(schemas)) {
+            return Collections.emptyMap();
+        }
+
+        for (Map.Entry<String, Schema> schemaEntry: schemas.entrySet()) {
+            if (existingComponentNames.contains(schemaEntry.getKey())) {
+                continue;
+            }
+            String modifiedName = getValidNameForType(schemaEntry.getKey());
+            if (modifiedName.equals(schemaEntry.getKey())) {
+                continue;
+            }
+            nameMap.put(schemaEntry.getKey(), modifiedName);
+        }
+        return getResolvedNameMapping(nameMap);
+    }
+
     private Filter getFilter() {
         List<String> tagList = new ArrayList<>();
         List<String> operationList = new ArrayList<>();

openapi-cli/src/main/resources/cli-help/ballerina-openapi-flatten.help

@@ -11,7 +11,7 @@ SYNOPSIS
 
 DESCRIPTION
        Flatten the OpenAPI contract file by moving all the inline schemas to the
-       components section.
+       components section. The generated schema names will be Ballerina friendly.
 
 OPTIONS
        -i, --input <openapi-contract-file-path>

openapi-cli/src/test/java/io/ballerina/openapi/cmd/OpenAPICmdTest.java

@@ -1015,6 +1015,16 @@ public void testFlattenCmdOperations() throws IOException {
         compareFiles(expectedFilePath, tmpDir.resolve("flattened_openapi.json"));
     }
 
+    @Test(description = "Test openapi flatten sub command with composed schema")
+    public void testFlattenCmdWithComposedSchema() throws IOException {
+        Path expectedFilePath = resourceDir.resolve(Paths.get("cmd/flatten/flattened_openapi_composed_schema.yaml"));
+        String[] args = {"-i", resourceDir + "/cmd/flatten/openapi_composed_schema.yaml", "-o", tmpDir.toString()};
+        Flatten flatten = new Flatten();
+        new CommandLine(flatten).parseArgs(args);
+        flatten.execute();
+        compareFiles(expectedFilePath, tmpDir.resolve("flattened_openapi.yaml"));
+    }
+
     @AfterTest
     public void clean() {
         System.setErr(null);

openapi-cli/src/test/resources/cmd/flatten/flattened_openapi_composed_schema.yaml

@@ -0,0 +1,150 @@
+openapi: 3.0.1
+info:
+  title: Swagger Petstore
+  license:
+    name: MIT
+  version: 1.0.0
+servers:
+  - url: /
+paths:
+  /pets:
+    get:
+      tags:
+        - pets
+      summary: List all pets
+      operationId: listPets
+      responses:
+        "200":
+          description: An paged array of pets
+          headers:
+            x-next:
+              description: A link to the next page of responses
+              style: simple
+              explode: false
+              schema:
+                type: string
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/InlineResponse200"
+    post:
+      tags:
+        - pets
+      summary: Create a pet
+      operationId: createPets
+      requestBody:
+        description: Created pet object
+        content:
+          application/json:
+            schema:
+              $ref: "#/components/schemas/PetsBody"
+        required: true
+      responses:
+        "201":
+          description: Null response
+  /pets/{petId}:
+    get:
+      tags:
+        - pets
+      summary: Info for a specific pet
+      operationId: showPetById
+      parameters:
+        - name: petId
+          in: path
+          description: The id of the pet to retrieve
+          required: true
+          style: simple
+          explode: false
+          schema:
+            type: integer
+            format: int64
+      responses:
+        "200":
+          description: Expected response to a valid request
+          content:
+            application/json:
+              schema:
+                $ref: "#/components/schemas/InlineResponse2001"
+  /locations:
+    get:
+      tags:
+        - locations
+      summary: List all locations
+      operationId: listLocations
+      parameters:
+        - name: area
+          in: query
+          description: area to filter by
+          required: false
+          style: form
+          explode: true
+          schema:
+            type: string
+      responses:
+        "200":
+          description: An paged array of locations
+          headers:
+            x-next:
+              description: A link to the next page of responses
+              style: simple
+              explode: false
+              schema:
+                type: string
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: "#/components/schemas/PetsOneOf1"
+components:
+  schemas:
+    PetspetsOneOf12:
+      type: object
+      properties:
+        name:
+          type: string
+        tag:
+          type: string
+    InlineResponse2001:
+      oneOf:
+        - type: object
+          properties:
+            id:
+              type: integer
+              format: int64
+            name:
+              type: string
+            tag:
+              type: string
+        - type: object
+          properties:
+            code:
+              type: integer
+            message:
+              type: string
+    InlineResponse200:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string
+    PetsOneOf1:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string
+    PetsBody:
+      oneOf:
+        - $ref: "#/components/schemas/PetsOneOf1"
+        - $ref: "#/components/schemas/PetspetsOneOf12"