Initial set of instructions to setup the development of this project (#46)

Author: jwren

README.md

@@ -1,3 +1,94 @@
+# Dart IntelliJ Plugin
+
+## Development setup
+
+1. Clone this repository with
+
+    ```shell
+    git clone [email protected]:flutter/dart-intellij-third-party.git
+    ```
+   
+2. Download the latest stable [IntelliJ Ultimate](https://www.jetbrains.com/idea/buy) or [IntelliJ Community](https://www.jetbrains.com/idea/download)
+3. From the "Welcome to IntelliJ IDEA" dialog, select "Open" and then select `third_party` directory in this repository.
+4. View > Tool Windows > Gradle, and click the button "Sync All Gradle Projects"
+5. The Java source code should now be compiled. To launch an IDE with this plugin, execute the following on the command line (from the `third_party` directory):
+
+    ```shell
+   ./gradlew runIde
+    ```
+
+### Gradle tasks
+
+This project is built with the [IntelliJ Platform Gradle Plugin](https://plugins.jetbrains.com/docs/intellij/tools-intellij-platform-gradle-plugin.html)
+
+To see all current and valid Gradle tasks execute
+```shell
+./gradlew tasks
+```
+
+A subset of the current output from `tasks` command:
+```
+----------------------------------------------------------
+Tasks runnable from root project 'Dart'
+------------------------------------------------------------
+
+Build tasks
+-----------
+assemble - Assembles the outputs of this project.
+build - Assembles and tests this project.
+...
+
+IDE tasks
+---------
+cleanIdea - Cleans IDEA project files (IML, IPR)
+idea - Generates IDEA project files (IML, IPR, IWS)
+openIdea - Opens the IDEA project
+
+Intellij platform tasks
+-----------------------
+buildPlugin - Builds the plugin and prepares the ZIP archive for testing and deployment.
+runIde - Runs the IDE instance using the currently selected IntelliJ Platform with the built plugin loaded.
+verifyPlugin - Runs the IntelliJ Plugin Verifier CLI tool to check the binary compatibility with specified IDE builds.
+...
+```
+
+### Tests
+
+To run **all** tests execute
+```shell
+./gradlew test
+```
+
+However, in the project tests are split between the unit tests under
+`src/main/test/java/com/jetbrains/lang/dart` and the Dart Analysis Server tests under
+`src/main/test/java/com/jetbrains/dart/analysisServer`.
+
+To run the **unit tests** on the command line run:
+```shell
+./gradlew test --tests "com.jetbrains.lang.dart.*"
+```
+
+To run the **Dart Analysis Server tests**, first set a `DART_HOME` (configured and set in
+`.github/workflows/presubmit.yaml` and in the tests themselves), then on the command line run:
+```shell
+./gradlew test --tests "com.jetbrains.dart.analysisServer.*"
+```
+
+These test suites can be configured as Gradle run configurations for running and debugging the tests from the IDE.
+
+Each of these test suites are run on GitHub presubmits, configured in `.github/workflows/presubmit.yaml`.
+
+### IntelliJ Plugin Verifier
+
+See `intellij-plugin-verifier`, https://github.com/JetBrains/intellij-plugin-verifier.
+
+To run the verifier run:
+```shell
+./gradlew verifyPlugin
+```
+
+The plugin verification is run on GitHub presubmits, configured in `.github/workflows/presubmit.yaml`.
+
 ## Project and repository history
 
 This repository was originally a copy of the [Dart Plugin for IntelliJ from JetBrains](https://github.com/JetBrains/intellij-plugins/tree/master/Dart) through the commit https://github.com/JetBrains/intellij-plugins/commit/c912b13b1dd8acccd6259dedc4063848a8f87b2b.