Add positive test cases

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

@@ -915,6 +915,106 @@ public void testAddCmd() throws IOException {
         Assert.assertTrue(tomlContent.contains(generatedTool));
     }
 
+    @Test(description = "Test openapi flatten sub command with default options with the json file")
+    public void testFlattenCmdDefaultJson() throws IOException {
+        Path expectedFilePath = resourceDir.resolve(Paths.get("cmd/flatten/flattened_openapi_expected.json"));
+        String[] args = {"-i", resourceDir + "/cmd/flatten/openapi.json", "-o", tmpDir.toString()};
+        Flatten flatten = new Flatten();
+        new CommandLine(flatten).parseArgs(args);
+        flatten.execute();
+        compareFiles(expectedFilePath, tmpDir.resolve("flattened_openapi.json"));
+    }
+
+    private void compareFiles(Path expectedFilePath, Path generatedFilePath) throws IOException {
+        if (Files.exists(generatedFilePath)) {
+            String expectedOpenAPIContent = "";
+            try (Stream<String> expectedOpenAPIContentLines = Files.lines(expectedFilePath)) {
+                expectedOpenAPIContent = expectedOpenAPIContentLines.collect(Collectors.joining(LINE_SEPARATOR));
+            } catch (IOException e) {
+                Files.deleteIfExists(generatedFilePath);
+                Assert.fail(e.getMessage());
+            }
+
+            String generatedOpenAPIContent = "";
+            try (Stream<String> generatedOpenAPIContentLines =
+                         Files.lines(generatedFilePath)) {
+                generatedOpenAPIContent = generatedOpenAPIContentLines.collect(Collectors.joining(LINE_SEPARATOR));
+            } catch (IOException e) {
+                Files.deleteIfExists(generatedFilePath);
+                Assert.fail(e.getMessage());
+            }
+
+            generatedOpenAPIContent = (generatedOpenAPIContent.trim()).replaceAll("\\s+", "");
+            expectedOpenAPIContent = (expectedOpenAPIContent.trim()).replaceAll("\\s+", "");
+            Assert.assertEquals(expectedOpenAPIContent, generatedOpenAPIContent);
+
+            Files.deleteIfExists(generatedFilePath);
+        } else {
+            Assert.fail("Generation failed: " + readOutput(true));
+        }
+    }
+
+    @Test(description = "Test openapi flatten sub command with default options with the yaml file")
+    public void testFlattenCmdDefaultYaml() throws IOException {
+        Path expectedFilePath = resourceDir.resolve(Paths.get("cmd/flatten/flattened_openapi_expected.yaml"));
+        String[] args = {"-i", resourceDir + "/cmd/flatten/openapi.yaml", "-o", tmpDir.toString()};
+        Flatten flatten = new Flatten();
+        new CommandLine(flatten).parseArgs(args);
+        flatten.execute();
+        compareFiles(expectedFilePath, tmpDir.resolve("flattened_openapi.yaml"));
+    }
+
+    @Test(description = "Test openapi flatten sub command with the name option")
+    public void testFlattenCmdName() throws IOException {
+        Path expectedFilePath = resourceDir.resolve(Paths.get("cmd/flatten/flattened_openapi_expected.json"));
+        String[] args = {"-i", resourceDir + "/cmd/flatten/openapi.json", "-o", tmpDir.toString(), "-n", "flattened"};
+        Flatten flatten = new Flatten();
+        new CommandLine(flatten).parseArgs(args);
+        flatten.execute();
+        compareFiles(expectedFilePath, tmpDir.resolve("flattened.json"));
+    }
+
+    @Test(description = "Test openapi flatten sub command with the json format option")
+    public void testFlattenCmdJsonFormat() throws IOException {
+        Path expectedFilePath = resourceDir.resolve(Paths.get("cmd/flatten/flattened_openapi_expected.json"));
+        String[] args = {"-i", resourceDir + "/cmd/flatten/openapi.yaml", "-o", tmpDir.toString(), "-f", "json"};
+        Flatten flatten = new Flatten();
+        new CommandLine(flatten).parseArgs(args);
+        flatten.execute();
+        compareFiles(expectedFilePath, tmpDir.resolve("flattened_openapi.json"));
+    }
+
+    @Test(description = "Test openapi flatten sub command with the yaml format option")
+    public void testFlattenCmdYamlFormat() throws IOException {
+        Path expectedFilePath = resourceDir.resolve(Paths.get("cmd/flatten/flattened_openapi_expected.yaml"));
+        String[] args = {"-i", resourceDir + "/cmd/flatten/openapi.json", "-o", tmpDir.toString(), "-f", "yaml"};
+        Flatten flatten = new Flatten();
+        new CommandLine(flatten).parseArgs(args);
+        flatten.execute();
+        compareFiles(expectedFilePath, tmpDir.resolve("flattened_openapi.yaml"));
+    }
+
+    @Test(description = "Test openapi flatten sub command with the tags option")
+    public void testFlattenCmdTags() throws IOException {
+        Path expectedFilePath = resourceDir.resolve(Paths.get("cmd/flatten/flattened_openapi_expected_pets.json"));
+        String[] args = {"-i", resourceDir + "/cmd/flatten/openapi.json", "-o", tmpDir.toString(), "-t", "pets"};
+        Flatten flatten = new Flatten();
+        new CommandLine(flatten).parseArgs(args);
+        flatten.execute();
+        compareFiles(expectedFilePath, tmpDir.resolve("flattened_openapi.json"));
+    }
+
+    @Test(description = "Test openapi flatten sub command with the operations option")
+    public void testFlattenCmdOperations() throws IOException {
+        Path expectedFilePath = resourceDir.resolve(Paths.get("cmd/flatten/flattened_openapi_expected_list_pets.json"));
+        String[] args = {"-i", resourceDir + "/cmd/flatten/openapi.json", "-o", tmpDir.toString(), "--operations",
+                "listPets"};
+        Flatten flatten = new Flatten();
+        new CommandLine(flatten).parseArgs(args);
+        flatten.execute();
+        compareFiles(expectedFilePath, tmpDir.resolve("flattened_openapi.json"));
+    }
+
     @AfterTest
     public void clean() {
         System.setErr(null);

openapi-cli/src/test/resources/cmd/flatten/flattened_openapi_expected.json

@@ -0,0 +1,145 @@
+{
+  "openapi" : "3.0.0",
+  "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"
+          }
+        }
+      }
+    },
+    "/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/PetsBody"
+                  }
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  "components" : {
+    "schemas" : {
+      "InlineResponse200" : {
+        "type" : "object",
+        "properties" : {
+          "id" : {
+            "type" : "integer",
+            "format" : "int64"
+          },
+          "name" : {
+            "type" : "string"
+          },
+          "tag" : {
+            "type" : "string"
+          }
+        }
+      },
+      "PetsBody" : {
+        "type" : "object",
+        "properties" : {
+          "id" : {
+            "type" : "integer",
+            "format" : "int64"
+          },
+          "name" : {
+            "type" : "string"
+          },
+          "tag" : {
+            "type" : "string"
+          }
+        }
+      }
+    }
+  }
+}

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

@@ -0,0 +1,99 @@
+openapi: 3.0.0
+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
+  /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/PetsBody"
+components:
+  schemas:
+    InlineResponse200:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string
+    PetsBody:
+      type: object
+      properties:
+        id:
+          type: integer
+          format: int64
+        name:
+          type: string
+        tag:
+          type: string