Extract AnvilBackend enum reference

compiler-api/src/main/java/com/squareup/anvil/compiler/api/AnvilBackend.kt

@@ -0,0 +1,10 @@
+package com.squareup.anvil.compiler.api
+
+/** Possible modes of Anvil compilation. */
+public enum class AnvilBackend {
+  /** Anvil runs as a direct compiler plugin inside compileKotlin tasks. */
+  EMBEDDED,
+
+  /** Anvil runs as a Kotlin Symbol Processor (KSP). */
+  KSP,
+}

compiler-api/src/main/java/com/squareup/anvil/compiler/api/AnvilContext.kt

@@ -30,7 +30,7 @@ public interface AnvilContext {
    * There are occasions where consumers of Anvil are only interested in generating Dagger
    * factories to speed up build times and don't want to make use of the other features. With this
    * flag Anvil will only generate Dagger factories and skip all other steps. If this flag is set
-   * to `true`, then also [generateDaggerFactories] must be set to `true`.
+   * to `true`, then also [generateFactories] must be set to `true`.
    */
   public val generateFactoriesOnly: Boolean
 

compiler-utils/src/testFixtures/java/com/squareup/anvil/compiler/internal/testing/AnvilCompilation.kt

@@ -75,7 +75,7 @@ public class AnvilCompilation internal constructor(
         PluginOption(
           pluginId = anvilCommandLineProcessor.pluginId,
           optionName = "compilation-mode",
-          optionValue = mode.type.name.lowercase(Locale.US)
+          optionValue = mode.backend.name.lowercase(Locale.US)
         )
       )
 

compiler-utils/src/testFixtures/java/com/squareup/anvil/compiler/internal/testing/AnvilCompilationMode.kt

@@ -1,15 +1,12 @@
 package com.squareup.anvil.compiler.internal.testing
 
 import com.google.devtools.ksp.processing.SymbolProcessorProvider
+import com.squareup.anvil.compiler.api.AnvilBackend
+import com.squareup.anvil.compiler.api.AnvilBackend.EMBEDDED
+import com.squareup.anvil.compiler.api.AnvilBackend.KSP
 import com.squareup.anvil.compiler.api.CodeGenerator
-import com.squareup.anvil.compiler.internal.testing.AnvilCompilationMode.Type.EMBEDDED
-import com.squareup.anvil.compiler.internal.testing.AnvilCompilationMode.Type.KSP
-
-sealed class AnvilCompilationMode(val type: Type) {
-  enum class Type {
-    EMBEDDED, KSP
-  }
 
+sealed class AnvilCompilationMode(val backend: AnvilBackend) {
   data class Embedded(
     val codeGenerators: List<CodeGenerator> = emptyList()
   ) : AnvilCompilationMode(EMBEDDED)

compiler/src/main/java/com/squareup/anvil/compiler/AnvilCommandLineProcessor.kt

@@ -1,6 +1,7 @@
 package com.squareup.anvil.compiler
 
 import com.google.auto.service.AutoService
+import com.squareup.anvil.compiler.api.AnvilBackend
 import org.jetbrains.kotlin.compiler.plugin.AbstractCliOption
 import org.jetbrains.kotlin.compiler.plugin.CliOption
 import org.jetbrains.kotlin.compiler.plugin.CommandLineProcessor
@@ -68,7 +69,7 @@ class AnvilCommandLineProcessor : CommandLineProcessor {
     ),
     CliOption(
       optionName = compilationModeName,
-      valueDescription = "<embedded|ksp>",
+      valueDescription = AnvilBackend.entries.joinToString("|", "<", ">"),
       description = "Controls whether Anvil is running as an embedded plugin or as KSP.",
       required = false,
       allowMultipleOccurrences = false

compiler/src/main/java/com/squareup/anvil/compiler/AnvilComponentRegistrar.kt

@@ -6,6 +6,7 @@ package com.squareup.anvil.compiler
 import com.google.auto.service.AutoService
 import com.squareup.anvil.annotations.ExperimentalAnvilApi
 import com.squareup.anvil.compiler.CommandLineOptions.Companion.commandLineOptions
+import com.squareup.anvil.compiler.api.AnvilBackend
 import com.squareup.anvil.compiler.api.CodeGenerator
 import com.squareup.anvil.compiler.codegen.BindingModuleGenerator
 import com.squareup.anvil.compiler.codegen.CodeGenerationExtension
@@ -57,7 +58,7 @@ class AnvilComponentRegistrar : ComponentRegistrar {
 
     // Everything below this point is only when running in embedded compilation mode. If running in
     // KSP, there's nothing else to do.
-    if (commandLineOptions.compilationMode != "embedded") {
+    if (commandLineOptions.backend != AnvilBackend.EMBEDDED) {
       return
     }
 

compiler/src/main/java/com/squareup/anvil/compiler/CommandLineOptions.kt

@@ -1,20 +1,25 @@
 package com.squareup.anvil.compiler
 
+import com.squareup.anvil.compiler.api.AnvilBackend
 import org.jetbrains.kotlin.config.CompilerConfiguration
+import java.util.Locale
 
 class CommandLineOptions private constructor(
   val generateFactories: Boolean,
   val generateFactoriesOnly: Boolean,
   val disableComponentMerging: Boolean,
-  val compilationMode: String,
+  val backend: AnvilBackend,
 ) {
   companion object {
     val CompilerConfiguration.commandLineOptions: CommandLineOptions
       get() = CommandLineOptions(
         generateFactories = get(generateDaggerFactoriesKey, false),
         generateFactoriesOnly = get(generateDaggerFactoriesOnlyKey, false),
         disableComponentMerging = get(disableComponentMergingKey, false),
-        compilationMode = get(compilationModeKey, "embedded"),
+        backend = get(compilationModeKey, AnvilBackend.EMBEDDED.name)
+          .uppercase(Locale.US)
+          .let { value -> AnvilBackend.entries.find { it.name == value } }
+          ?: error("Unknown backend option: $this"),
       )
   }
 }