CodeBlock throwing IAE because CassName does not pass is TypeName check

Question

I tried to initialize a property, though CodeBlock#of throws an IllegalArgumentException in CodeBlock#argToType

I looked into the root cause of the error which was at CodeBlock#argToType. Even if o is a ClassName(which also is a TypeName) it does not pass the is TypeName -> o check and throws the IllegalArguementException.

val initString = "mutableMapOf(Pair(%T, %T), Pair(%T, %T))"
val initArgs = arraysOf(...)
CodeBlock.of(initString, initArgs)

I expected the CodeBlock to be built correctly, but instead it throws the IllegalArguementException

Answer 1

I reproduced you problem and was able to fix it; I think the key question is how you pass initArgs to CodeBlock.of: this method is expecting a second varargs parameter but you're passing a single Array<...> value.

Changing you code as follows seems to work:

fun main(args: Array<String>) {
    val initString = "mutableMapOf(Pair(%T, %T), Pair(%T, %T))"
    val initArgs = arrayOf(String::class.java, String::class.java, String::class.java, String::class.java)
    val result = CodeBlock.of(initString, *initArgs)
    println("result is $result")
}

The key point is to pass *initArgs, and not initArgs, as second parameter of CodeBlock.of.

I explicitly initialized initArgs' values witch type values, in order to match %T placeholder expectations.

I hope this can help you!