feat: scaffold new Kotlin projects in a more idiomatic way (#584)

Also added an integration test that verifies that `ftl init kotlin`
works.

Procfile.integration

@@ -1,3 +1,4 @@
 controller: build/release/ftl-controller --key C01H5BRT09Y07547SETZ4HWRA09 --bind http://localhost:8892
 runner0: build/release/ftl-runner --key R01H5BTS6ABP1EHGZSAGJMBV50A --language go --language kotlin --bind http://localhost:8894 --template-dir build/template --deployment-dir build/runner0
 runner1: build/release/ftl-runner --key R01H5BTSGKQ8AZ9S22N9N1SM9HV --language go --language kotlin --bind http://localhost:8895 --template-dir build/template --deployment-dir build/runner1
+runner2: build/release/ftl-runner --key R01H8DD0Z5GRT3QP1MBARC4TW08 --language go --language kotlin --bind http://localhost:8896 --template-dir build/template --deployment-dir build/runner2

cmd/ftl/cmd_init.go

@@ -31,8 +31,10 @@ func (i initGoCmd) Run(parent *initCmd) error {
 }
 
 type initKotlinCmd struct {
-	Dir  string `arg:"" default:"." help:"Directory to initialize the module in."`
-	Name string `short:"n" help:"Name of the FTL module (defaults to name of directory)."`
+	GroupID    string `short:"g" help:"Base Maven group ID (defaults to \"ftl\")." default:"ftl"`
+	ArtifactID string `short:"a" help:"Base Maven artifact ID (defaults to \"ftl\")." default:"ftl"`
+	Name       string `short:"n" help:"Name of the FTL module (defaults to name of directory)."`
+	Dir        string `arg:"" default:"." help:"Directory to initialize the module in."`
 }
 
 func (i *initKotlinCmd) Run(parent *initCmd) error {

kotlin-runtime/scaffolding/ftl-module-{{ .Name | lower }}/pom.xml

@@ -0,0 +1,9 @@
+<project xmlns="http://maven.apache.org/POM/4.0.0"
+    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
+
+    <modelVersion>4.0.0</modelVersion>
+    <groupId>ftl</groupId>
+    <artifactId>ftl-module-{{ .Name | camel | lower }}</artifactId>
+    <version>1.0-SNAPSHOT</version>
+</project>

kotlin-runtime/scaffolding/pom.xml

@@ -1,12 +1,19 @@
-<project xmlns="http://maven.apache.org/POM/4.0.0"
-    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+<?xml version="1.0" encoding="UTF-8"?>
+<project xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+    xmlns="http://maven.apache.org/POM/4.0.0"
     xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
-
     <modelVersion>4.0.0</modelVersion>
-    <groupId>ftl</groupId>
-    <artifactId>ftl-module-{{ .Name | camel | lower }}</artifactId>
+
+    <groupId>{{ .GroupID }}</groupId>
+    <artifactId>{{ .ArtifactID }}</artifactId>
     <version>1.0-SNAPSHOT</version>
 
+    <packaging>pom</packaging>
+
+    <modules>
+        <module>ftl-module-{{ .Name | camel | lower }}</module>
+    </modules>
+
     <properties>
         <ftl.version>1.0-SNAPSHOT</ftl.version>
         <java.version>11</java.version>
@@ -27,11 +34,6 @@
             <artifactId>ftl-runtime</artifactId>
             <version>${ftl.version}</version>
         </dependency>
-        <dependency>
-            <groupId>xyz.block</groupId>
-            <artifactId>ftl-generator</artifactId>
-            <version>${ftl.version}</version>
-        </dependency>
     </dependencies>
 
     <build>

scripts/integration-tests

@@ -57,6 +57,15 @@ deploy_echo_kotlin() (
   ftl deploy target
 )
 
+deploy_fresh_kotlin() (
+  info "Deploying newly initialised Kotlin module"
+  rm -rf build/echo2
+  ftl init kotlin -n echo2 build/echo2
+  cd build/echo2
+  mvn compile
+  ftl deploy target
+)
+
 deploy_time_go() (
   info "Deploying time"
   cd examples
@@ -66,7 +75,7 @@ deploy_time_go() (
 )
 
 wait_for_deploys() {
-  wait_for "deployments to come up" 'ftl status | jq -r ".routes[].module" | sort | paste -sd " " - | grep -q "echo time"'
+  wait_for "deployments to come up" 'ftl status | jq -r ".routes[].module" | sort | paste -sd " " - | grep -q "echo echo2 time"'
 }
 
 build_release
@@ -76,10 +85,14 @@ start_cluster
 # Cluster is up, start interacting with it.
 deploy_time_go
 deploy_echo_kotlin
+deploy_fresh_kotlin
 
 wait_for_deploys
 
 info "Calling echo"
 message="$(ftl call echo.echo '{"name": "Alice"}' | jq -r .message)"
 [[ "$message" =~ "Hello, Alice! The time is " ]] || error "Unexpected response from echo: $message"
+
+message="$(ftl call echo2.echo '{"name": "Alice"}' | jq -r .message)"
+[[ "$message" =~ "Hello, Alice!" ]] || error "Unexpected response from echo2: $message"
 info "Success!"