Reasonable names or burstValues symbols (#46)

* Reasonable names or burstValues symbols

* Spotless

---------

Co-authored-by: Jesse Wilson <[email protected]>

burst-kotlin-plugin-tests/src/test/kotlin/app/cash/burst/kotlin/BurstKotlinPluginTest.kt

@@ -18,6 +18,7 @@ package app.cash.burst.kotlin
 import assertk.assertThat
 import assertk.assertions.contains
 import assertk.assertions.containsExactly
+import assertk.assertions.containsExactlyInAnyOrder
 import assertk.assertions.isFalse
 import assertk.assertions.isTrue
 import com.tschuchort.compiletesting.JvmCompilationResult
@@ -306,6 +307,66 @@ class BurstKotlinPluginTest {
     assertThat(baseLog).containsExactly("running 16")
     baseLog.clear()
   }
+
+  @Test
+  fun burstValuesHasReasonableSymbolName() {
+    val result = compile(
+      sourceFile = SourceFile.kotlin(
+        "CoffeeTest.kt",
+        """
+        import app.cash.burst.Burst
+        import app.cash.burst.burstValues
+        import kotlin.math.PI
+        import kotlin.math.abs
+        import kotlin.test.Test
+
+        @Burst
+        class CoffeeTest {
+          @Test
+          fun test(
+            content: Any? = burstValues(
+              3, // No name is generated for the first value.
+              "5".toInt(),
+              "hello",
+              "hello".uppercase(),
+              CoffeeTest::class,
+              Float.MAX_VALUE,
+              PI,
+              String.CASE_INSENSITIVE_ORDER,
+              abs(1),
+              null,
+            )
+          ) {
+          }
+        }
+        """,
+      ),
+    )
+    assertEquals(KotlinCompilation.ExitCode.OK, result.exitCode, result.messages)
+
+    val baseClass = result.classLoader.loadClass("CoffeeTest")
+    assertThat(baseClass.testSuffixes).containsExactlyInAnyOrder(
+      "toInt",
+      "hello",
+      "uppercase",
+      "CoffeeTest",
+      // Would have preferred 'MAX_VALUE', but this is constant is inlined!
+      "3_4028235E38",
+      // Would have preferred 'PI', but this is constant is inlined!
+      "3_141592653589793",
+      "CASE_INSENSITIVE_ORDER",
+      "abs",
+      "null",
+    )
+  }
+
+  private val Class<*>.testSuffixes: List<String>
+    get() = methods.mapNotNull {
+      when {
+        it.name.startsWith("test_") -> it.name.substring(5)
+        else -> null
+      }
+    }
 }
 
 @ExperimentalCompilerApi

burst-kotlin-plugin/src/main/kotlin/app/cash/burst/kotlin/Argument.kt

@@ -22,17 +22,20 @@ import org.jetbrains.kotlin.ir.declarations.IrClass
 import org.jetbrains.kotlin.ir.declarations.IrEnumEntry
 import org.jetbrains.kotlin.ir.declarations.IrValueParameter
 import org.jetbrains.kotlin.ir.expressions.IrCall
+import org.jetbrains.kotlin.ir.expressions.IrClassReference
 import org.jetbrains.kotlin.ir.expressions.IrConst
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrGetEnumValue
 import org.jetbrains.kotlin.ir.expressions.IrVararg
 import org.jetbrains.kotlin.ir.expressions.impl.IrGetEnumValueImpl
 import org.jetbrains.kotlin.ir.symbols.UnsafeDuringIrConstructionAPI
 import org.jetbrains.kotlin.ir.types.IrType
+import org.jetbrains.kotlin.ir.types.classFqName
 import org.jetbrains.kotlin.ir.types.getClass
 import org.jetbrains.kotlin.ir.util.classId
 import org.jetbrains.kotlin.ir.util.deepCopyWithSymbols
 import org.jetbrains.kotlin.ir.util.isEnumClass
+import org.jetbrains.kotlin.name.NameUtils
 
 internal sealed interface Argument {
   /** True if this argument matches the default parameter value. */
@@ -59,17 +62,9 @@ private class EnumValueArgument(
 
 private class BurstValuesArgument(
   override val isDefault: Boolean,
+  override val name: String,
   private val value: IrExpression,
-  private val index: Int,
 ) : Argument {
-  override val name: String
-    get() {
-      return when {
-        value is IrConst<*> -> value.value.toString()
-        else -> index.toString()
-      }
-    }
-
   override fun expression() = value.deepCopyWithSymbols()
 }
 
@@ -113,26 +108,57 @@ private fun burstValuesArguments(
   burstApisCall: IrCall,
 ): List<Argument> {
   return buildList {
+    val defaultExpression = burstApisCall.valueArguments[0] ?: unexpectedParameter(parameter)
     add(
       BurstValuesArgument(
         isDefault = true,
-        value = burstApisCall.valueArguments[0] ?: unexpectedParameter(parameter),
-        index = 0,
+        name = defaultExpression.suggestedName() ?: "0",
+        value = defaultExpression,
       ),
     )
 
     for ((index, element) in (burstApisCall.valueArguments[1] as IrVararg).elements.withIndex()) {
+      val varargExpression = element as? IrExpression ?: unexpectedParameter(parameter)
       add(
         BurstValuesArgument(
           isDefault = false,
-          value = element as? IrExpression ?: unexpectedParameter(parameter),
-          index = index + 1,
+          name = varargExpression.suggestedName() ?: (index + 1).toString(),
+          value = varargExpression,
         ),
       )
     }
   }
 }
 
+/**
+ * Returns a short name for this expression appropriate for use in a generated symbol declaration.
+ *
+ * If this is a constant like 'hello' or '3.14', this returns the value as a string.
+ *
+ * If this is a call like `String.CASE_INSENSITIVE_ORDER` or `abs(-5)`, this returns the name of the
+ * called symbol (`CASE_INSENSITIVE_ORDER` or `abs`), discarding the receiver, value parameters, and
+ * type parameters.
+ *
+ * If this is a class reference like `String::class`, this returns the type's simple name.
+ */
+@UnsafeDuringIrConstructionAPI
+private fun IrExpression.suggestedName(): String? {
+  val raw = when (this) {
+    is IrConst<*> -> value.toString()
+    is IrCall -> {
+      val target = (symbol.owner.correspondingPropertySymbol?.owner ?: symbol.owner)
+      target.name.asString()
+    }
+
+    is IrClassReference -> classType.classFqName?.shortName()?.asString() ?: return null
+    else -> return null
+  }
+
+  // Calling sanitizeAsJavaIdentifier is necessary but not sufficient. We assume further phases of
+  // the compiler will make the returned name safe for the ultimate compilation target.
+  return NameUtils.sanitizeAsJavaIdentifier(raw)
+}
+
 @UnsafeDuringIrConstructionAPI
 private fun enumValueArguments(
   referenceClass: IrClass,