Add string interpolation support in codegen

Author: sofurihafe

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/domain/models/CgElement.kt

@@ -87,6 +87,7 @@ interface CgElement {
             is CgNotNullAssertion -> visit(element)
             is CgVariable -> visit(element)
             is CgParameterDeclaration -> visit(element)
+            is CgFormattedString -> visit(element)
             is CgLiteral -> visit(element)
             is CgNonStaticRunnable -> visit(element)
             is CgStaticRunnable -> visit(element)
@@ -823,6 +824,11 @@ class CgArrayInitializer(val arrayType: ClassId, val elementType: ClassId, val v
 
 class CgSpread(override val type: ClassId, val array: CgExpression) : CgExpression
 
+// Interpolated string
+// e.g. String.format() for Java, "${}" for Kotlin
+
+class CgFormattedString(val array: List<CgExpression>) : CgElement
+
 // Enum constant
 
 data class CgEnumConstantAccess(

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/renderer/CgAbstractRenderer.kt

@@ -595,7 +595,11 @@ abstract class CgAbstractRenderer(
     // Primitive and String literals
 
     override fun visit(element: CgLiteral) {
-        val value = with(element.value) {
+        print(element.toStringConstant())
+    }
+
+    protected fun CgLiteral.toStringConstant(asRawString: Boolean = false) =
+        with(this.value) {
             when (this) {
                 is Byte -> toStringConstant()
                 is Char -> toStringConstant()
@@ -605,12 +609,11 @@ abstract class CgAbstractRenderer(
                 is Float -> toStringConstant()
                 is Double -> toStringConstant()
                 is Boolean -> toStringConstant()
-                is String -> toStringConstant()
+                // String is "\"" + "str" + "\"", RawString is "str"
+                is String -> if (asRawString) "$this".escapeCharacters() else toStringConstant()
                 else -> "$this"
             }
         }
-        print(value)
-    }
 
     // Non-static runnable like this::toString or (new Object())::toString etc
     override fun visit(element: CgNonStaticRunnable) {
@@ -924,7 +927,7 @@ abstract class CgAbstractRenderer(
     private fun Boolean.toStringConstant() =
         if (this) "true" else "false"
 
-    private fun String.toStringConstant(): String = "\"" + escapeCharacters() + "\""
+    protected fun String.toStringConstant(): String = "\"" + escapeCharacters() + "\""
 
     protected abstract fun String.escapeCharacters(): String
 

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/renderer/CgJavaRenderer.kt

@@ -32,6 +32,8 @@ import org.utbot.framework.codegen.domain.models.CgSwitchCase
 import org.utbot.framework.codegen.domain.models.CgSwitchCaseLabel
 import org.utbot.framework.codegen.domain.models.CgClass
 import org.utbot.framework.codegen.domain.models.CgClassBody
+import org.utbot.framework.codegen.domain.models.CgFormattedString
+import org.utbot.framework.codegen.domain.models.CgLiteral
 import org.utbot.framework.codegen.domain.models.CgTestMethod
 import org.utbot.framework.codegen.domain.models.CgTypeCast
 import org.utbot.framework.codegen.domain.models.CgVariable
@@ -320,6 +322,27 @@ internal class CgJavaRenderer(context: CgRendererContext, printer: CgPrinter = C
         println("}")
     }
 
+    override fun visit(element: CgFormattedString) {
+        val nonLiteralElements = element.array.filterNot { it is CgLiteral }
+
+        print("String.format(")
+        val constructedMsg = buildString {
+            element.array.forEachIndexed { index, cgElement ->
+                if (cgElement is CgLiteral) append(
+                    cgElement.toStringConstant(asRawString = true)
+                ) else append("%s")
+                if (index < element.array.lastIndex) append(" ")
+            }
+        }
+
+        print(constructedMsg.toStringConstant())
+
+        // Comma to separate msg from variables
+        if (nonLiteralElements.isNotEmpty()) print(", ")
+        nonLiteralElements.renderSeparated(newLines = false)
+        print(")")
+    }
+
     override fun toStringConstantImpl(byte: Byte): String = "(byte) $byte"
 
     override fun toStringConstantImpl(short: Short): String = "(short) $short"

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/renderer/CgKotlinRenderer.kt

@@ -38,8 +38,11 @@ import org.utbot.framework.codegen.domain.models.CgSwitchCase
 import org.utbot.framework.codegen.domain.models.CgSwitchCaseLabel
 import org.utbot.framework.codegen.domain.models.CgClass
 import org.utbot.framework.codegen.domain.models.CgClassBody
+import org.utbot.framework.codegen.domain.models.CgFormattedString
+import org.utbot.framework.codegen.domain.models.CgLiteral
 import org.utbot.framework.codegen.domain.models.CgTestMethod
 import org.utbot.framework.codegen.domain.models.CgTypeCast
+import org.utbot.framework.codegen.domain.models.CgValue
 import org.utbot.framework.codegen.domain.models.CgVariable
 import org.utbot.framework.codegen.util.nullLiteral
 import org.utbot.framework.plugin.api.BuiltinClassId
@@ -480,6 +483,29 @@ internal class CgKotlinRenderer(context: CgRendererContext, printer: CgPrinter =
         println("}")
     }
 
+    override fun visit(element: CgFormattedString) {
+        print("\"")
+        element.array.forEachIndexed { index, cgElement ->
+            if (cgElement is CgLiteral)
+                print(cgElement.toStringConstant(asRawString = true))
+            else {
+                print("$")
+                when (cgElement) {
+                    // It is not necessary to wrap variables with curly brackets
+                    is CgVariable -> cgElement.accept(this)
+                    else -> {
+                        print("{")
+                        cgElement.accept(this)
+                        print("}")
+                    }
+                }
+            }
+
+            if (index < element.array.lastIndex) print(" ")
+        }
+        print("\"")
+    }
+
     override fun toStringConstantImpl(byte: Byte): String = buildString {
         if (byte < 0) {
             append("(")

utbot-framework/src/main/kotlin/org/utbot/framework/codegen/renderer/CgVisitor.kt

@@ -76,6 +76,7 @@ import org.utbot.framework.codegen.domain.models.CgSwitchCaseLabel
 import org.utbot.framework.codegen.domain.models.CgClass
 import org.utbot.framework.codegen.domain.models.CgClassBody
 import org.utbot.framework.codegen.domain.models.CgDocRegularLineStmt
+import org.utbot.framework.codegen.domain.models.CgFormattedString
 import org.utbot.framework.codegen.domain.models.CgNestedClassesRegion
 import org.utbot.framework.codegen.domain.models.CgTestMethod
 import org.utbot.framework.codegen.domain.models.CgTestMethodCluster
@@ -223,6 +224,9 @@ interface CgVisitor<R> {
     // Spread operator
     fun visit(element: CgSpread): R
 
+    // Formatted string
+    fun visit(element: CgFormattedString): R
+
     // Enum constant
     fun visit(element: CgEnumConstantAccess): R
 

utbot-js/src/main/kotlin/framework/codegen/model/constructor/visitor/CgJsRenderer.kt

@@ -21,6 +21,7 @@ import org.utbot.framework.codegen.domain.models.CgExecutableCall
 import org.utbot.framework.codegen.domain.models.CgExpression
 import org.utbot.framework.codegen.domain.models.CgFieldAccess
 import org.utbot.framework.codegen.domain.models.CgForLoop
+import org.utbot.framework.codegen.domain.models.CgFormattedString
 import org.utbot.framework.codegen.domain.models.CgGetJavaClass
 import org.utbot.framework.codegen.domain.models.CgGetKotlinClass
 import org.utbot.framework.codegen.domain.models.CgGetLength
@@ -340,6 +341,10 @@ internal class CgJsRenderer(context: CgRendererContext, printer: CgPrinter = CgP
         }
     }
 
+    override fun visit(element: CgFormattedString) {
+        throw NotImplementedError("String interpolation is not supported in JavaScript renderer")
+    }
+
     //TODO MINOR: check
     override fun renderForLoopVarControl(element: CgForLoop) {
         print("for (")

utbot-python/src/main/kotlin/org/utbot/python/framework/codegen/model/constructor/visitor/CgPythonRenderer.kt

@@ -28,6 +28,7 @@ import org.utbot.framework.codegen.domain.models.CgExecutableCall
 import org.utbot.framework.codegen.domain.models.CgExpression
 import org.utbot.framework.codegen.domain.models.CgForEachLoop
 import org.utbot.framework.codegen.domain.models.CgForLoop
+import org.utbot.framework.codegen.domain.models.CgFormattedString
 import org.utbot.framework.codegen.domain.models.CgGetJavaClass
 import org.utbot.framework.codegen.domain.models.CgGetKotlinClass
 import org.utbot.framework.codegen.domain.models.CgGetLength
@@ -530,6 +531,10 @@ internal class CgPythonRenderer(
         print(element.value.toString())
     }
 
+    override fun visit(element: CgFormattedString) {
+        throw NotImplementedError("String interpolation is not supported in Python renderer")
+    }
+
     override fun String.escapeCharacters(): String =
         StringEscapeUtils
             .escapeJava(this)