[Assign plugin] Add a compiler plugin for overloading assign ('=') operator

plugins/assign-plugin/testData/codegen/annotation.kt

@@ -0,0 +1,120 @@
+// FILE: JavaProperty.java
+@ValueContainer
+public interface JavaProperty<T> {
+    void assign(T argument);
+    T get();
+}
+
+// FILE: JavaClassStringProperty.java
+@ValueContainer
+public class JavaClassStringProperty {
+    private String v;
+
+    public JavaClassStringProperty(String v) {
+        this.v = v;
+    }
+
+    public void assign(String v) {
+        this.v = v;
+    }
+    public String get() {
+        return v;
+    }
+}
+
+// FILE: test.kt
+annotation class ValueContainer
+
+data class JavaStringProperty(private var v: String): JavaProperty<String> {
+    override fun assign(v: String) {
+        this.v = v
+    }
+    override fun get() = this.v
+}
+
+@ValueContainer
+interface KotlinProperty<T> {
+    fun assign(argument: T);
+    fun get(): T;
+}
+
+data class KotlinStringProperty(private var v: String): KotlinProperty<String> {
+    override fun assign(v: String) {
+        this.v = v
+    }
+    override fun get() = this.v
+}
+
+@ValueContainer
+data class KotlinClassStringProperty(private var v: String) {
+    fun assign(v: String) {
+        this.v = v
+    }
+    fun get(): String {
+        return v
+    }
+}
+
+fun `should work with annotation on Java interface`(): String {
+    data class Task(val input: JavaStringProperty)
+    val task = Task(JavaStringProperty("Fail"))
+    task.input = "OK"
+
+    return if (task.input.get() != "OK") {
+        "Fail: ${task.input.get()}"
+    } else {
+        "OK"
+    }
+}
+
+fun `should work with annotation on Java class`(): String {
+    data class Task(val input: JavaClassStringProperty)
+    val task = Task(JavaClassStringProperty("Fail"))
+    task.input = "OK"
+
+    return if (task.input.get() != "OK") {
+        "Fail: ${task.input.get()}"
+    } else {
+        "OK"
+    }
+}
+
+fun `should work with annotation on Kotlin interface`(): String {
+    data class Task(val input: KotlinStringProperty)
+    val task = Task(KotlinStringProperty("Fail"))
+    task.input = "OK"
+
+    return if (task.input.get() != "OK") {
+        "Fail: ${task.input.get()}"
+    } else {
+        "OK"
+    }
+}
+
+fun `should work with annotation on Kotlin class`(): String {
+    data class Task(val input: KotlinClassStringProperty)
+    val task = Task(KotlinClassStringProperty("Fail"))
+    task.input = "OK"
+
+    return if (task.input.get() != "OK") {
+        "Fail: ${task.input.get()}"
+    } else {
+        "OK"
+    }
+}
+
+fun box(): String {
+    var result = `should work with annotation on Java interface`()
+    if (result != "OK") return result
+
+    result = `should work with annotation on Java class`()
+    if (result != "OK") return result
+
+    result = `should work with annotation on Kotlin interface`()
+    if (result != "OK") return result
+
+    result = `should work with annotation on Kotlin class`()
+    if (result != "OK") return result
+
+    return "OK"
+}