Introduce code style and reformat existing code #403 (#579)

* Introduce code style and reformat existing code #403

* Add check-code-style.yml workflow #403

* Add graphql-codegen-check-style.xml and enable it in the workflow #403

* Fix check-code-style.yml workflow

* Fix build issues

* Revert back changes in gradlew script

Author: kobylynskyi

.github/ISSUE_TEMPLATE/bug_report.md

@@ -12,21 +12,25 @@ assignees: ''
 *Describe your bug in detail.*
 
 ## Steps to Reproduce
+
 *List in detail the exact steps to reproduce the unexpected behavior.*
 
 ## Expected Result
+
 *Explain in detail what behavior you expected to happen.*
 
 ## Actual Result
+
 *Explain in detail what behavior actually happened.*
 
 ## Your Environment and Setup
 
 * **graphql-java-codegen version**: *X.X.X*
 * **Build tool**: *E.g.: Maven/Gradle/SBT*
-* **Mapping Config**: *E.g.:* 
+* **Mapping Config**: *E.g.:*
 
 ```xml
+
 <configuration>
     <outputDir>${project.build.directory}/generated-sources/graphql</outputDir>
     <packageName>io.github.kobylynskyi.graphql.model</packageName>

.github/workflows/check-code-style.yml

@@ -0,0 +1,33 @@
+name: Check Code Style
+
+on:
+  push:
+    branches:
+      - master
+      - develop
+  pull_request:
+    branches:
+      - master
+      - develop
+
+jobs:
+  check-code-style:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v2
+
+      - name: Check Code Style
+        env:
+          WORKDIR: ./
+          REVIEWDOG_GITHUB_API_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+          CHECKSTYLE_CONFIG: config/checkstyle/graphql-codegen-check-style.xml
+          REVIEWDOG_VERSION: v0.11.0
+        run: |
+          wget -O - -q https://github.com/checkstyle/checkstyle/releases/download/checkstyle-8.41/checkstyle-8.41-all.jar > /opt/checkstyle.jar
+          wget -O - -q https://raw.githubusercontent.com/reviewdog/reviewdog/master/install.sh | sh -s -- -b /opt ${REVIEWDOG_VERSION}
+          java -jar /opt/checkstyle.jar "${WORKDIR}" -c "${CHECKSTYLE_CONFIG}"  -f xml \
+               | /opt/reviewdog -f=checkstyle \
+                    -reporter="${INPUT_REPORTER:-github-pr-check}" \
+                    -filter-mode="${INPUT_FILTER_MODE:-added}" \
+                    -fail-on-error="${INPUT_FAIL_ON_ERROR:-false}"

.github/workflows/github.yml

@@ -15,7 +15,7 @@ jobs:
     runs-on: ubuntu-latest
     strategy:
       matrix:
-        jdk-version: [1.8]
+        jdk-version: [ 1.8 ]
     steps:
       - uses: actions/checkout@v2
 

CONTRIBUTING.md

@@ -11,22 +11,24 @@ Before sending your pull requests, make sure you followed this list:
 - Build the project locally.
 - Run Unit Tests and ensure that you have the test coverage for your code.
 
-
 ## Development process
 
 Please follow the steps below in order to make the changes:
 
-1. Clone the repository and open it in your favourite IDE.
+1. Clone the repository
 2. Checkout **develop** branch.
-3. Make code changes to the core library of `graphql-java-codegen`.
-4. If changes are required in the plugin code, then **build** and **install** `graphql-java-codegen` first.
+3. Open repository in your favourite IDE.
+4. Enable and configure CheckStyle plugin in your IDE (for IntelliJ it is CheckStyle-IDEA).
+   Import [graphql-codegen-check-style.xml](config/checkstyle/graphql-codegen-check-style.xml) as a .
+5. Make code changes to the core library of `graphql-java-codegen`.
+6. If changes are required in the plugin code, then **build** and **install** `graphql-java-codegen` first.
 
    ```shell script
    # This will install the library (including your recent changes) in your local maven repository.
    ./gradlew clean build publishToMavenLocal
    ```
-   
-5. Build the plugin project with updated `graphql-java-codegen` library.
+
+7. Build the plugin project with updated `graphql-java-codegen` library.
 
    ```shell script
    # Build Gradle plugin
@@ -37,8 +39,8 @@ Please follow the steps below in order to make the changes:
    mvn clean verify 
    ```
 
-6. Make changes to the plugin code
-7. Install the plugin (copy to your local maven repository).
+8. Make changes to the plugin code
+9. Install the plugin (copy to your local maven repository).
 
    ```shell script
    # Install Gradle plugin
@@ -49,4 +51,4 @@ Please follow the steps below in order to make the changes:
    mvn clean install 
    ```
 
-8. Make sure that `example` projects are compiling and running.
+10. Make sure that `example` projects are compiling and running.

config/checkstyle/checkstyle-suppressions.xml

@@ -0,0 +1,43 @@
+<?xml version="1.0"?>
+<!DOCTYPE suppressions PUBLIC
+        "-//Checkstyle//DTD SuppressionFilter Configuration 1.2//EN"
+        "https://checkstyle.org/dtds/suppressions_1_2.dtd">
+
+<suppressions>
+    <suppress checks=".*"
+              files=".*[/\\]target[/\\]"/>
+    <suppress checks=".*"
+              files=".*[/\\]build[/\\]"/>
+    <suppress checks=".*"
+              files=".*[/\\]generated.*[/\\]"/>
+
+    <suppress checks="MissingJavadocMethod"
+              files="[\\/]test[\\/]"/>
+    <suppress checks="MissingJavadocType"
+              files="[\\/]test[\\/]"/>
+    <suppress checks="SingleLineJavadoc"
+              files="[\\/]test[\\/]"/>
+    <suppress checks="AvoidEscapedUnicodeCharacters"
+              files="[\\/]test[\\/]"/>
+    <suppress checks="VariableDeclarationUsageDistance"
+              files="[\\/]test[\\/]"/>
+    <suppress checks="TypeName"
+              files="[\\/]test[\\/]"/>
+    <suppress checks="MissingJavadocMethod"
+              files="[\\/]example.*[\\/]"/>
+    <suppress checks="MissingJavadocType"
+              files="[\\/]example.*[\\/]"/>
+
+    <suppress checks="LineLength"
+              files="GraphQLCodegenGradleTask\.java"
+              lines="0-100"/>
+
+    <suppress checks="MethodName"
+              files="GraphQLResponseProjection\.java"/>
+
+    <suppress checks="MemberName"
+              message="Member name '\$alias'.*"/>
+
+    <suppress checks="CustomImportOrder"
+              message="Wrong lexicographical order for 'java\.[^']+' import\. Should be before 'javax\.[^']+'\."/>
+</suppressions>