[Dart 2] Add support for Dart 2 (OpenAPITools#754)

* Add an option for Dart2

* add dart2 samples, update travis

* fix dart installation

* Upper constraints on the SDK version

* Update dependencies

* supportDart2 option can now be passed through --additional-properties

* Update petstore tests

* Update dart2-petstore.sh

* Running tests on Dart VM

* Fixed JSON deserialization bugs

* Fixed missing initialization of postBody

* Run bin/dart2-petstore.sh to regenerate libraries

* Update pom.xml

* Added SDK version constraints in pubspec.mustache

* Run bin/dart2-petstore.sh to regenerate libraries

* move dart2 test to the end

Author: Yimin Lin

.travis.yml

@@ -30,6 +30,7 @@ cache:
   - $HOME/perl5
   - $HOME/.cargo
   - $HOME/.stack
+  - $HOME/.pub-cache
   - $HOME/samples/server/petstore/cpp-pistache/pistache
   - $HOME/.npm  
   - $HOME/.rvm/gems/ruby-2.4.1
@@ -72,6 +73,13 @@ before_install:
   - sudo apt-get update -qq
   - sudo apt-get install -qq bats
   - sudo apt-get install -qq curl
+  # install dart
+  #- sudo apt-get update
+  - sudo apt-get install apt-transport-https
+  - sudo sh -c 'curl https://dl-ssl.google.com/linux/linux_signing_key.pub | apt-key add -'
+  - sudo sh -c 'curl https://storage.googleapis.com/download.dartlang.org/linux/debian/dart_stable.list > /etc/apt/sources.list.d/dart_stable.list'
+  - sudo apt-get update
+  - sudo apt-get install dart
   # install perl module
   #- cpanm --local-lib=~/perl5 local::lib && eval $(perl -I ~/perl5/lib/perl5/ -Mlocal::lib)
   #- cpanm Test::Exception Test::More Log::Any LWP::UserAgent JSON URI:Query Module::Runtime DateTime Module::Find Moose::Role
@@ -96,11 +104,13 @@ install:
   # Add Godeps dependencies to GOPATH and PATH
   #- eval "$(curl -sL https://raw.githubusercontent.com/travis-ci/gimme/master/gimme | GIMME_GO_VERSION=1.4 bash)"
   #- export GOPATH="${TRAVIS_BUILD_DIR}/Godeps/_workspace"
-  - export PATH="${TRAVIS_BUILD_DIR}/Godeps/_workspace/bin:$HOME/.cargo/bin:$PATH"
+  - export PATH="${TRAVIS_BUILD_DIR}/Godeps/_workspace/bin:$HOME/.cargo/bin:$PATH:/usr/lib/dart/bin"
   #- go version
   - gcc -v
   - echo $CC
   - echo $CXX
+  - pub version
+  - dart --version
 
 script:
   # fail fast

bin/dart2-petstore.sh

@@ -0,0 +1,50 @@
+#!/bin/sh
+
+SCRIPT="$0"
+echo "# START SCRIPT: $SCRIPT"
+
+while [ -h "$SCRIPT" ] ; do
+  ls=`ls -ld "$SCRIPT"`
+  link=`expr "$ls" : '.*-> \(.*\)$'`
+  if expr "$link" : '/.*' > /dev/null; then
+    SCRIPT="$link"
+  else
+    SCRIPT=`dirname "$SCRIPT"`/"$link"
+  fi
+done
+
+if [ ! -d "${APP_DIR}" ]; then
+  APP_DIR=`dirname "$SCRIPT"`/..
+  APP_DIR=`cd "${APP_DIR}"; pwd`
+fi
+
+executable="./modules/openapi-generator-cli/target/openapi-generator-cli.jar"
+
+if [ ! -f "$executable" ]
+then
+  mvn -B clean package
+fi
+
+# if you've executed sbt assembly previously it will use that instead.
+export JAVA_OPTS="${JAVA_OPTS} -XX:MaxPermSize=256M -Xmx1024M -DloggerPath=conf/log4j.properties"
+
+# Generate non-browserClient
+ags="generate -t modules/openapi-generator/src/main/resources/dart -i modules/openapi-generator/src/test/resources/2_0/petstore.yaml -g dart -o samples/client/petstore/dart2/openapi -DhideGenerationTimestamp=true -DbrowserClient=false --additional-properties supportDart2=true $@"
+
+# then options to generate the library for vm would be:
+#ags="generate -i modules/openapi-generator/src/test/resources/2_0/petstore.yaml -g dart -o samples/client/petstore/dart2/openapi_vm -DbrowserClient=false -DpubName=openapi_vm $@"
+java $JAVA_OPTS -jar $executable $ags
+
+# Generate browserClient
+ags="generate -t modules/openapi-generator/src/main/resources/dart -i modules/openapi-generator/src/test/resources/2_0/petstore.yaml -g dart -o samples/client/petstore/dart2/openapi-browser-client -DhideGenerationTimestamp=true -DbrowserClient=true --additional-properties supportDart2=true $@"
+java $JAVA_OPTS -jar $executable $ags
+
+# Generate non-browserClient and put it to the flutter sample app
+ags="generate -t modules/openapi-generator/src/main/resources/dart -i modules/openapi-generator/src/test/resources/2_0/petstore.yaml -g dart -o samples/client/petstore/dart2/flutter_petstore/openapi -DhideGenerationTimestamp=true -DbrowserClient=false --additional-properties supportDart2=true $@"
+java $JAVA_OPTS -jar $executable $ags
+
+# There is a proposal to allow importing different libraries depending on the environment:
+# https://github.com/munificent/dep-interface-libraries
+# When this is implemented there will only be one library.
+
+# The current petstore test will then work for both: the browser library and the vm library.

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

@@ -28,6 +28,7 @@
 import org.openapitools.codegen.utils.ModelUtils;
 
 import io.swagger.v3.oas.models.media.*;
+import io.swagger.v3.parser.util.SchemaTypeUtil;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -48,6 +49,7 @@ public class DartClientCodegen extends DefaultCodegen implements CodegenConfig {
     public static final String PUB_VERSION = "pubVersion";
     public static final String PUB_DESCRIPTION = "pubDescription";
     public static final String USE_ENUM_EXTENSION = "useEnumExtension";
+    public static final String SUPPORT_DART2 = "supportDart2";
     protected boolean browserClient = true;
     protected String pubName = "openapi";
     protected String pubVersion = "1.0.0";
@@ -125,6 +127,7 @@ public DartClientCodegen() {
         cliOptions.add(new CliOption(PUB_DESCRIPTION, "Description in generated pubspec"));
         cliOptions.add(new CliOption(USE_ENUM_EXTENSION, "Allow the 'x-enum-values' extension for enums"));
         cliOptions.add(new CliOption(CodegenConstants.SOURCE_FOLDER, "source folder for generated code"));
+        cliOptions.add(CliOption.newBoolean(SUPPORT_DART2, "support dart2").defaultValue(Boolean.FALSE.toString()));
     }
 
     @Override
@@ -189,9 +192,14 @@ public void processOpts() {
         additionalProperties.put("apiDocPath", apiDocPath);
         additionalProperties.put("modelDocPath", modelDocPath);
 
+        final Object isSupportDart2 = additionalProperties.get(SUPPORT_DART2);
+        if (Boolean.TRUE.equals(isSupportDart2) || (isSupportDart2 instanceof String && Boolean.parseBoolean((String)isSupportDart2))) {
+            embeddedTemplateDir = templateDir = "dart2";
+        } else {
+            supportingFiles.add(new SupportingFile("analysis_options.mustache", "", ".analysis_options"));
+        }
         final String libFolder = sourceFolder + File.separator + "lib";
         supportingFiles.add(new SupportingFile("pubspec.mustache", "", "pubspec.yaml"));
-        supportingFiles.add(new SupportingFile("analysis_options.mustache", "", ".analysis_options"));
         supportingFiles.add(new SupportingFile("api_client.mustache", libFolder, "api_client.dart"));
         supportingFiles.add(new SupportingFile("api_exception.mustache", libFolder, "api_exception.dart"));
         supportingFiles.add(new SupportingFile("api_helper.mustache", libFolder, "api_helper.dart"));

modules/openapi-generator/src/main/resources/dart2/README.mustache

@@ -0,0 +1,133 @@
+# {{pubName}}
+{{#appDescription}}
+{{{appDescription}}}
+{{/appDescription}}
+
+This Dart package is automatically generated by the [OpenAPI Generator](https://openapi-generator.tech) project:
+
+- API version: {{appVersion}}
+{{#artifactVersion}}
+- Package version: {{artifactVersion}}
+{{/artifactVersion}}
+{{^hideGenerationTimestamp}}
+- Build date: {{generatedDate}}
+{{/hideGenerationTimestamp}}
+- Build package: {{generatorClass}}
+{{#infoUrl}}
+For more information, please visit [{{{infoUrl}}}]({{{infoUrl}}})
+{{/infoUrl}}
+
+## Requirements
+
+Dart 1.20.0 or later OR Flutter 0.0.20 or later
+
+## Installation & Usage
+
+### Github
+If this Dart package is published to Github, please include the following in pubspec.yaml
+```
+name: {{pubName}}
+version: {{pubVersion}}
+description: {{pubDescription}}
+dependencies:
+  {{pubName}}:
+    git: https://github.com/{{gitUserId}}/{{gitRepoId}}.git
+      version: 'any'
+```
+
+### Local
+To use the package in your local drive, please include the following in pubspec.yaml
+```
+dependencies:
+  {{pubName}}:
+    path: /path/to/{{pubName}}
+```
+
+## Tests
+
+TODO
+
+## Getting Started
+
+Please follow the [installation procedure](#installation--usage) and then run the following:
+
+```dart
+import 'package:{{pubName}}/api.dart';
+{{#apiInfo}}{{#apis}}{{#-first}}{{#operations}}{{#operation}}{{#-first}}
+{{#hasAuthMethods}}
+{{#authMethods}}
+{{#isBasic}}
+// TODO Configure HTTP basic authorization: {{{name}}}
+//{{pubName}}.api.Configuration.username = 'YOUR_USERNAME';
+//{{pubName}}.api.Configuration.password = 'YOUR_PASSWORD';
+{{/isBasic}}
+{{#isApiKey}}
+// TODO Configure API key authorization: {{{name}}}
+//{{pubName}}.api.Configuration.apiKey{'{{{keyParamName}}}'} = 'YOUR_API_KEY';
+// uncomment below to setup prefix (e.g. Bearer) for API key, if needed
+//{{pubName}}.api.Configuration.apiKeyPrefix{'{{{keyParamName}}}'} = "Bearer";
+{{/isApiKey}}
+{{#isOAuth}}
+// TODO Configure OAuth2 access token for authorization: {{{name}}}
+//{{pubName}}.api.Configuration.accessToken = 'YOUR_ACCESS_TOKEN';
+{{/isOAuth}}
+{{/authMethods}}
+{{/hasAuthMethods}}
+
+var api_instance = new {{classname}}();
+{{#allParams}}
+var {{paramName}} = {{#isListContainer}}[{{/isListContainer}}{{#isBodyParam}}new {{dataType}}(){{/isBodyParam}}{{^isBodyParam}}{{{example}}}{{/isBodyParam}}{{#isListContainer}}]{{/isListContainer}}; // {{{dataType}}} | {{{description}}}
+{{/allParams}}
+
+try {
+    {{#returnType}}var result = {{/returnType}}api_instance.{{{operationId}}}({{#allParams}}{{paramName}}{{#hasMore}}, {{/hasMore}}{{/allParams}});
+    {{#returnType}}
+    print(result);
+    {{/returnType}}
+} catch (e) {
+    print("Exception when calling {{classname}}->{{operationId}}: $e\n");
+}
+{{/-first}}{{/operation}}{{/operations}}{{/-first}}{{/apis}}{{/apiInfo}}
+```
+
+## Documentation for API Endpoints
+
+All URIs are relative to *{{basePath}}*
+
+Class | Method | HTTP request | Description
+------------ | ------------- | ------------- | -------------
+{{#apiInfo}}{{#apis}}{{#operations}}{{#operation}}*{{classname}}* | [**{{operationId}}**]({{apiDocPath}}/{{classname}}.md#{{operationIdLowerCase}}) | **{{httpMethod}}** {{path}} | {{#summary}}{{summary}}{{/summary}}
+{{/operation}}{{/operations}}{{/apis}}{{/apiInfo}}
+
+## Documentation For Models
+
+{{#models}}{{#model}} - [{{{classname}}}]({{modelDocPath}}/{{{classname}}}.md)
+{{/model}}{{/models}}
+
+## Documentation For Authorization
+
+{{^authMethods}} All endpoints do not require authorization.
+{{/authMethods}}{{#authMethods}}{{#last}} Authentication schemes defined for the API:{{/last}}{{/authMethods}}
+{{#authMethods}}## {{{name}}}
+
+{{#isApiKey}}- **Type**: API key
+- **API key parameter name**: {{{keyParamName}}}
+- **Location**: {{#isKeyInQuery}}URL query string{{/isKeyInQuery}}{{#isKeyInHeader}}HTTP header{{/isKeyInHeader}}
+{{/isApiKey}}
+{{#isBasic}}- **Type**: HTTP basic authentication
+{{/isBasic}}
+{{#isOAuth}}- **Type**: OAuth
+- **Flow**: {{{flow}}}
+- **Authorization URL**: {{{authorizationUrl}}}
+- **Scopes**: {{^scopes}}N/A{{/scopes}}
+{{#scopes}} - **{{{scope}}}**: {{{description}}}
+{{/scopes}}
+{{/isOAuth}}
+
+{{/authMethods}}
+
+## Author
+
+{{#apiInfo}}{{#apis}}{{^hasMore}}{{infoEmail}}
+{{/hasMore}}{{/apis}}{{/apiInfo}}
+

modules/openapi-generator/src/main/resources/dart2/api.mustache

@@ -0,0 +1,117 @@
+part of {{pubName}}.api;
+
+{{#operations}}
+
+
+class {{classname}} {
+  final ApiClient apiClient;
+
+  {{classname}}([ApiClient apiClient]) : apiClient = apiClient ?? defaultApiClient;
+
+  {{#operation}}
+  /// {{summary}}
+  ///
+  /// {{notes}}
+  {{#returnType}}Future<{{{returnType}}}> {{/returnType}}{{^returnType}}Future {{/returnType}}{{nickname}}({{#allParams}}{{#required}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/required}}{{/allParams}}{{#hasOptionalParams}}{ {{#allParams}}{{^required}}{{{dataType}}} {{paramName}}{{#hasMore}}, {{/hasMore}}{{/required}}{{/allParams}} }{{/hasOptionalParams}}) async {
+    Object postBody{{#bodyParam}} = {{paramName}}{{/bodyParam}};
+
+    // verify required params are set
+    {{#allParams}}
+      {{#required}}
+    if({{paramName}} == null) {
+     throw new ApiException(400, "Missing required param: {{paramName}}");
+    }
+      {{/required}}
+    {{/allParams}}
+
+    // create path and map variables
+    String path = "{{{path}}}".replaceAll("{format}","json"){{#pathParams}}.replaceAll("{" + "{{baseName}}" + "}", {{{paramName}}}.toString()){{/pathParams}};
+
+    // query params
+    List<QueryParam> queryParams = [];
+    Map<String, String> headerParams = {};
+    Map<String, String> formParams = {};
+    {{#queryParams}}
+    {{^required}}
+    if({{paramName}} != null) {
+    {{/required}}
+      queryParams.addAll(_convertParametersForCollectionFormat("{{collectionFormat}}", "{{baseName}}", {{paramName}}));
+    {{^required}}
+    }
+    {{/required}}
+    {{/queryParams}}
+    {{#headerParams}}
+    headerParams["{{baseName}}"] = {{paramName}};
+    {{/headerParams}}
+
+    List<String> contentTypes = [{{#consumes}}"{{{mediaType}}}"{{#hasMore}},{{/hasMore}}{{/consumes}}];
+
+    String contentType = contentTypes.length > 0 ? contentTypes[0] : "application/json";
+    List<String> authNames = [{{#authMethods}}"{{name}}"{{#hasMore}}, {{/hasMore}}{{/authMethods}}];
+
+    if(contentType.startsWith("multipart/form-data")) {
+      bool hasFields = false;
+      MultipartRequest mp = new MultipartRequest(null, null);
+      {{#formParams}}
+      {{^isFile}}
+      if ({{paramName}} != null) {
+        hasFields = true;
+        mp.fields['{{baseName}}'] = parameterToString({{paramName}});
+      }
+      {{/isFile}}
+      {{#isFile}}
+      if ({{paramName}} != null) {
+        hasFields = true;
+        mp.fields['{{baseName}}'] = {{paramName}}.field;
+        mp.files.add({{paramName}});
+      }
+      {{/isFile}}
+      {{/formParams}}
+      if(hasFields)
+        postBody = mp;
+    }
+    else {
+      {{#formParams}}
+      {{^isFile}}
+      if ({{paramName}} != null)
+        formParams['{{baseName}}'] = parameterToString({{paramName}});
+      {{/isFile}}
+      {{/formParams}}
+    }
+
+    var response = await apiClient.invokeAPI(path,
+                                             '{{httpMethod}}',
+                                             queryParams,
+                                             postBody,
+                                             headerParams,
+                                             formParams,
+                                             contentType,
+                                             authNames);
+
+    if(response.statusCode >= 400) {
+      throw new ApiException(response.statusCode, response.body);
+    } else if(response.body != null) {
+      {{#isListContainer}}
+        {{#returnType}}
+      return (apiClient.deserialize(response.body, '{{{returnType}}}') as List).map((item) => item as {{returnBaseType}}).toList();
+        {{/returnType}}
+      {{/isListContainer}}
+      {{^isListContainer}}
+        {{#isMapContainer}}
+          {{#returnType}}
+      return new {{{returnType}}}.from(apiClient.deserialize(response.body, '{{{returnType}}}'));
+          {{/returnType}};
+        {{/isMapContainer}}
+        {{^isMapContainer}}
+          {{#returnType}}
+      return apiClient.deserialize(response.body, '{{{returnType}}}') as {{{returnType}}};
+          {{/returnType}}
+        {{/isMapContainer}}
+      {{/isListContainer}}
+    } else {
+      return{{#returnType}} null{{/returnType}};
+    }
+  }
+  {{/operation}}
+}
+{{/operations}}