WIP Py3 bindings

generator-api/src/main/java/org/coursera/courier/api/DefaultGeneratorRunner.java

@@ -131,7 +131,8 @@ private void deleteUnrecognizedFiles(
         (Collection<File>)FileUtils.listFiles(targetDirectory, null, true);
 
     for (File existingFile : existingFiles) {
-      if (!targetFiles.contains(existingFile)) {
+      // TODO(py3): Get rid of this terrible __init__.py hack before un-WIPping this PR
+      if (!targetFiles.contains(existingFile) && !existingFile.getAbsoluteFile().getName().contains("__init__.py")) {
         FileUtils.forceDelete(existingFile);
       }
     }
@@ -176,6 +177,15 @@ private static File writeCode(
               directory.getAbsolutePath());
     }
 
+    // TODO(py3): Get rid of this before PRing for god sake. Find a better way to do this in courier
+    File py3Init = new File(directory, "__init__.py");
+    System.err.println(py3Init.getAbsolutePath());
+    if (!py3Init.exists()) {
+      if (!py3Init.createNewFile()) {
+        throw new IllegalArgumentException("Unable to create file " + py3Init.getAbsolutePath());
+      }
+    }
+
     if (!file.exists()) {
       if (!file.createNewFile()) {
         throw new IllegalArgumentException("unable to create file: " + file.getAbsolutePath());

project/Build.scala

@@ -155,19 +155,25 @@ object Courier extends Build with OverridablePublishSettings {
   lazy val typescriptLiteGenerator = Project(id = "typescript-lite-generator", base = typescriptLiteDir / "generator")
     .dependsOn(generatorApi)
 
+  private[this] val python3Dir = file("python3")
+  lazy val python3Generator = Project(id = "python3-generator", base = python3Dir / "generator")
+    .dependsOn(generatorApi)
+
   lazy val cli = Project(id = "courier-cli", base = file("cli"))
     .dependsOn(
       javaGenerator,
       androidGenerator,
       scalaGenerator,
       typescriptLiteGenerator,
-      swiftGenerator
+      swiftGenerator,
+      python3Generator
     ).aggregate(
       javaGenerator,
       androidGenerator,
       scalaGenerator,
       typescriptLiteGenerator,
-      swiftGenerator
+      swiftGenerator,
+      python3Generator
     ).settings(
       executableFile := {
         val exeFile = target.value / "courier"
@@ -187,6 +193,11 @@ object Courier extends Build with OverridablePublishSettings {
     id = "typescript-lite-generator-test", base = typescriptLiteDir / "generator-test")
     .dependsOn(typescriptLiteGenerator)
 
+  lazy val python3GeneratorTest = Project(
+    id = "python3-generator-test", base = python3Dir / "generator-test")
+    .dependsOn(python3Generator)
+
+
   lazy val courierSbtPlugin = Project(id = "sbt-plugin", base = file("sbt-plugin"))
     .dependsOn(scalaGenerator)
 
@@ -218,6 +229,7 @@ object Courier extends Build with OverridablePublishSettings {
     s";project android-runtime;$publishCommand" +
     s";project swift-generator;$publishCommand" +
     s";project typescript-lite-generator;$publishCommand" +
+    s";project python3-generator;$publishCommand" +
     s";++$sbtScalaVersion;project scala-generator;$publishCommand" +
     s";++$currentScalaVersion;project scala-generator;$publishCommand" +
     s";++$sbtScalaVersion;project sbt-plugin;$publishCommand" +

python3/.gitignore

@@ -0,0 +1,11 @@
+.gradle
+build/
+
+generator/build
+testsuite/testsuiteTests/generated
+
+# Ignore Gradle GUI config
+gradle-app.setting
+
+# Avoid ignoring Gradle wrapper jar file (.jar files are usually ignored)
+!gradle-wrapper.jar

python3/README.md

@@ -0,0 +1,67 @@
+Python3 Courier Data Binding Generator
+==============================================
+
+Courier bindings for Python 3 (tested against Python 3.6)
+
+Features missing in action
+--------------------------
+
+Mainline Courier features that are not yet supported, but will be by the time
+this thing is ready for submit:
+  - [ ] **Coercers**
+  - [ ] **Non-primitive keyed maps**. Hashcode not yet implemented for
+        non-primitives.
+  - [ ] **Non-JSON serialization**. Though avro should be trivial with existing
+        avro libraries.
+  - [ ] **Default values**.
+  - [ ] **Flat-typed definitions**.
+  - [ ] **Optional fields**. Currently all fields in `MyRecord.create` are
+        required. These should be easy to add.
+  - [ ] **Deprecation**.
+  - [ ] **Enum properties**. No `Fruits.BANANA.property("color")`
+  - [ ] **$UNKNOWN** on enums.
+
+Additional tasks before merging to courier master:
+  - [ ] Fix the most heinous `TODO` items from the changelist.
+    - Specifically the ones that alter the general, not-only-py3 code.
+  - [ ] Hook into the top-level cli
+  - [ ] Many additional test-cases
+  - [ ] Populate this documentation
+
+Additional desirable tasks for later:
+  - [ ] Ship `courier.py` as a package through `pip` instead of through the
+        generator
+  - [ ] Examine abstractions that unify code the large amount of overlap between TSLite and Python3 code generation.
+        Hopefully this can lead to writing new bindings more easily down the road.
+
+Running the generator from the command line
+-------------------------------------------
+
+Build a fat jar from source and use that. 
+
+```bash
+$ sbt
+> project python3-generator
+> assembly
+# Wait for a bit...
+[info] Packaging /Users/eboto/code/courier/python3/generator/target/courier-python3-generator-2.0.8.jar ...
+```
+
+To see usage, execute `java -jar <the generated jar>`
+
+Runtime library
+---------------
+
+All generated Python3 bindings depend on a `courier.py` class. This class provides the consistent
+runtime aspect necessary for generated bindings to work. It is shipped with the bindings.
+
+Testing
+-------
+
+Not-that-exhaustive tests are run against the reference suite. To execute them:
+
+```bash
+$ sbt
+> project python3-generator-test
+> test
+```

python3/generator-test/build.sbt

@@ -0,0 +1,49 @@
+import sbt.inc.Analysis
+
+name := "courier-python3-generator-test"
+
+packagedArtifacts := Map.empty // do not publish
+
+libraryDependencies ++= Seq(
+  ExternalDependencies.JodaTime.jodaTime)
+
+autoScalaLibrary := false
+
+crossPaths := false
+
+// Test Generator
+forkedVmCourierGeneratorSettings
+
+forkedVmCourierMainClass := "org.coursera.courier.Python3Generator"
+
+forkedVmCourierClasspath := (dependencyClasspath in Runtime in python3Generator).value.files
+
+forkedVmSourceDirectory := (sourceDirectory in referenceSuite).value / "main" / "courier"
+
+forkedVmCourierDest := file("python3") / "testsuite" / "src" / "py3bindings"
+
+forkedVmAdditionalArgs := Seq("STRICT")
+
+(compile in Compile) := {
+  (forkedVmCourierGenerator in Compile).value
+
+  Analysis.Empty
+}
+
+lazy val py3Test = taskKey[Boolean]("Executes python unittest")
+
+py3Test in Test := {
+  // Comment out the following line to just run the tests without
+  // new generation.
+  (compile in Compile).value
+
+  val result = """./python3/testsuite/full-build.sh"""!
+
+  if (result != 0) {
+    throw new RuntimeException("Python3 Build Failed")
+  }
+
+  true
+}
+
+test in Test := (py3Test in Test).value

python3/generator/.gitignore

@@ -0,0 +1,2 @@
+src/test/mainGeneratedPegasus
+src/main/mainGeneratedPegasus

python3/generator/build.sbt

@@ -0,0 +1,19 @@
+import sbtassembly.AssemblyPlugin.defaultShellScript
+
+name := "courier-python3-generator"
+
+plainJavaProjectSettings
+
+libraryDependencies ++= Seq(
+  ExternalDependencies.Rythm.rythmEngine,
+  ExternalDependencies.Slf4j.slf4jSimple,
+  ExternalDependencies.Pegasus.dataAvro
+)
+
+// Fat Jar
+mainClass in assembly := Some("org.coursera.courier.Python3Generator")
+
+assemblyOption in assembly := (assemblyOption in assembly).value.copy(prependShellScript = Some(defaultShellScript))
+
+assemblyJarName in assembly := s"${name.value}-${version.value}.jar"
+