Change command-line flags (#212)

Instead of `--emit-kotlin`, we're adding a `--lang` option defaulting to Java. Instead of `--use-java-style-names`, we're adding `--name-style` defaulting to, well, "default", but that can also be "java" (or potentially other styles as well).

This change also attempts to infer language if it is unspecified - in this case, if `--kt-file-per-type` is specified, but `--lang` is not, we assume that `--lang=kotlin` was intended.

Fixes #209

#209 envisioned a bigger revamp of the CLI, but on further thought we don't need to go to such lengths. Just providing options (instead of boolean flags) for a few params and introducing `--lang` are enough to keep the CLI reasonable.

build.gradle

@@ -28,7 +28,7 @@ allprojects {
     version VERSION
 
     project.ext {
-        kotlin_version = '1.2.51'
+        kotlin_version = '1.2.60'
 
         libraries = [
                 clikt: [

thrifty-compiler/build.gradle

@@ -59,7 +59,7 @@ task compileTestCase(type: Exec) {
     dependsOn jarTask
 
     executable 'java'
-    args = ['-jar', jarTask.archivePath.absolutePath, "--use-java-style-names", "--out=$projectDir/build/generated-src/gen/java", "$projectDir/TestThrift.thrift"]
+    args = ['-jar', jarTask.archivePath.absolutePath, "--name-style=java", "--out=$projectDir/build/generated-src/gen/java", "$projectDir/TestThrift.thrift"]
 }
 
 afterEvaluate {

thrifty-compiler/src/main/kotlin/com/microsoft/thrifty/compiler/ThriftyCompiler.kt

@@ -24,11 +24,13 @@ import com.github.ajalt.clikt.core.CliktCommand
 import com.github.ajalt.clikt.output.TermUi
 import com.github.ajalt.clikt.parameters.arguments.argument
 import com.github.ajalt.clikt.parameters.arguments.multiple
+import com.github.ajalt.clikt.parameters.options.default
 import com.github.ajalt.clikt.parameters.options.flag
 import com.github.ajalt.clikt.parameters.options.multiple
 import com.github.ajalt.clikt.parameters.options.option
 import com.github.ajalt.clikt.parameters.options.required
 import com.github.ajalt.clikt.parameters.options.validate
+import com.github.ajalt.clikt.parameters.types.choice
 import com.github.ajalt.clikt.parameters.types.path
 import com.microsoft.thrifty.gen.ThriftyCodeGenerator
 import com.microsoft.thrifty.kgen.KotlinCodeGenerator
@@ -51,6 +53,10 @@ import java.util.ArrayList
  * [--list-type=java.util.ArrayList]
  * [--set-type=java.util.HashSet]
  * [--map-type=java.util.HashMap]
+ * [--lang=[java|kotlin]]
+ * [--kt-file-per-type]
+ * [--parcelable]
+ * [--use-android-annotations]
  * file1.thrift
  * file2.thrift
  * ...
@@ -79,7 +85,15 @@ import java.util.ArrayList
  */
 class ThriftyCompiler {
 
-    private val cli = object : CliktCommand(name = "thrifty-compiler") {
+    enum class Language {
+        JAVA,
+        KOTLIN
+    }
+
+    private val cli = object : CliktCommand(
+            name = "thrifty-compiler",
+            help = "Generate Java or Kotlin code from .thrift files"
+    ) {
         val outputDirectory: Path by option("-o", "--out", help = "the output directory for generated files")
                 .path(fileOkay = false, folderOkay = true)
                 .required()
@@ -89,6 +103,16 @@ class ThriftyCompiler {
                 .path(exists = true, folderOkay = true, fileOkay = false)
                 .multiple()
 
+        val language: Language? by option(
+                        "-l", "--lang", help = "the target language for generated code.  Default is java.")
+                .choice("java" to Language.JAVA, "kotlin" to Language.KOTLIN)
+
+        val nameStyle: FieldNamingPolicy by option(
+                        "--name-style",
+                        help = "Format style for generated names.  Default is to leave names unaltered.")
+                .choice("default" to FieldNamingPolicy.DEFAULT, "java" to FieldNamingPolicy.JAVA)
+                .default(FieldNamingPolicy.DEFAULT)
+
         val listTypeName: String? by option("--list-type", help = "when specified, the concrete type to use for lists")
         val setTypeName: String? by option("--set-type", help =  "when specified, the concrete type to use for sets")
         val mapTypeName: String? by option("--map-type", help = "when specified, the concrete type to use for maps")
@@ -101,13 +125,6 @@ class ThriftyCompiler {
                     help = "When set, generates Parcelable implementations for structs")
                 .flag(default = false)
 
-        val useJavaStyleNames by option("--use-java-style-names",
-                    help = "When set, converts field names to standard java camelCase")
-                .flag(default = false)
-
-        val emitKotlin: Boolean by option("--kotlin", help = "Generate Kotlin instead of Java")
-                .flag(default = false)
-
         val kotlinFilePerType: Boolean by option(
                     "--kt-file-per-type", help = "Generate one .kt file per type; default is one per namespace.")
                 .flag(default = false)
@@ -139,17 +156,27 @@ class ThriftyCompiler {
                 return
             }
 
-            val fieldNamingPolicy = if (useJavaStyleNames) FieldNamingPolicy.JAVA else FieldNamingPolicy.DEFAULT
+            val impliedLanguage = when {
+                kotlinFilePerType -> Language.KOTLIN
+                emitNullabilityAnnotations -> Language.JAVA
+                else -> null
+            }
 
-            if (emitKotlin) {
-                generateKotlin(schema, fieldNamingPolicy)
-            } else {
-                generateJava(schema, fieldNamingPolicy)
+            if (language != null && impliedLanguage != language) {
+                TermUi.echo(
+                        "You specified $language, but provided options implying $impliedLanguage (which will be ignored).",
+                        err = true)
+            }
+
+            when (language ?: impliedLanguage) {
+                null,
+                Language.JAVA -> generateJava(schema)
+                Language.KOTLIN -> generateKotlin(schema)
             }
         }
 
-        private fun generateJava(schema: Schema, fieldNamingPolicy: FieldNamingPolicy) {
-            var gen = ThriftyCodeGenerator(schema, fieldNamingPolicy)
+        private fun generateJava(schema: Schema) {
+            var gen = ThriftyCodeGenerator(schema, nameStyle)
             listTypeName?.let { gen = gen.withListType(it) }
             setTypeName?.let { gen = gen.withSetType(it) }
             mapTypeName?.let { gen = gen.withMapType(it) }
@@ -166,8 +193,16 @@ class ThriftyCompiler {
             gen.generate(outputDirectory)
         }
 
-        private fun generateKotlin(schema: Schema, fieldNamingPolicy: FieldNamingPolicy) {
-            val gen = KotlinCodeGenerator(fieldNamingPolicy)
+        private fun generateKotlin(schema: Schema) {
+            val gen = KotlinCodeGenerator(nameStyle)
+
+            if (emitNullabilityAnnotations) {
+                TermUi.echo("Warning: Nullability annotations are unnecessary in Kotlin and will not be generated")
+            }
+
+            if (emitParcelable) {
+                TermUi.echo("Warning: Parcel generation not yet implemented for Kotlin codegen")
+            }
 
             if (kotlinFilePerType) {
                 gen.filePerType()

thrifty-integration-tests/build.gradle

@@ -75,7 +75,7 @@ task kompileTestThrift(type: Exec) {
     dependsOn jarTask
 
     executable 'java'
-    args = ['-jar', jarTask.archivePath.absolutePath, "--out=$projectDir/build/generated-src/thrifty/kotlin", "--kotlin", "$projectDir/ClientThriftTest.thrift"]
+    args = ['-jar', jarTask.archivePath.absolutePath, "--out=$projectDir/build/generated-src/thrifty/kotlin", "--lang=kotlin", "$projectDir/ClientThriftTest.thrift"]
 }
 
 compileTestKotlin {