[Wasm] Mocha test framework support

libraries/kotlin.test/wasm/src/main/kotlin/kotlin/test/JasmineLikeAdapter.kt

@@ -6,19 +6,29 @@
 package kotlin.test
 
 import kotlin.test.FrameworkAdapter
+import kotlin.js.Promise
 
 // Need to wrap into additional lambdas so that js launcher will work without Mocha or any other testing framework
 @JsFun("(name, fn) => describe(name, fn)")
-internal external fun describe(name: String, fn: () -> Unit)
+private external fun describe(name: String, fn: () -> Unit)
 
 @JsFun("(name, fn) => xdescribe(name, fn)")
-internal external fun xdescribe(name: String, fn: () -> Unit)
+private external fun xdescribe(name: String, fn: () -> Unit)
 
 @JsFun("(name, fn) => it(name, fn)")
-internal external fun it(name: String, fn: () -> Any?)
+private external fun it(name: String, fn: () -> Any?)
 
 @JsFun("(name, fn) => xit(name, fn)")
-internal external fun xit(name: String, fn: () -> Any?)
+private external fun xit(name: String, fn: () -> Any?)
+
+@JsFun("(e) => { throw e }")
+private external fun jsThrow(jsException: Dynamic)
+
+@JsFun("(message, stack) => { const e = new Error(); e.message = message; e.stack = stack; return e; }")
+private external fun throwableToJsError(message: String, stack: String): Dynamic
+
+private fun Throwable.toJsError(): Dynamic =
+    throwableToJsError(message ?: "", stackTraceToString())
 
 /**
  * [Jasmine](https://github.com/jasmine/jasmine) adapter.
@@ -33,11 +43,29 @@ internal class JasmineLikeAdapter : FrameworkAdapter {
         }
     }
 
+    private fun callTest(testFn: () -> Any?): Any? =
+        try {
+            (testFn() as? Promise<*>)?.catch { exception ->
+                val jsException = exception
+                    .toThrowableOrNull()
+                    ?.let { it.toJsError() }
+                    ?: exception
+                Promise.reject(jsException) as Dynamic
+            }
+        } catch (exception: Throwable) {
+            jsThrow(exception.toJsError())
+            null
+        }
+
     override fun test(name: String, ignored: Boolean, testFn: () -> Any?) {
         if (ignored) {
-            xit(name, testFn)
+            xit(name) {
+                callTest(testFn)
+            }
         } else {
-            it(name, testFn)
+            it(name) {
+                callTest(testFn)
+            }
         }
     }
 }

libraries/kotlin.test/wasm/src/main/kotlin/kotlin/test/TestApi.kt

@@ -30,14 +30,23 @@ internal fun setAdapter(adapter: FrameworkAdapter) {
  */
 
 internal fun suite(name: String, ignored: Boolean, suiteFn: () -> Unit) {
-    currentAdapter.suite(name, ignored, suiteFn)
+    adapter().suite(name, ignored, suiteFn)
 }
 
 internal fun test(name: String, ignored: Boolean, testFn: () -> Any?) {
-    currentAdapter.test(name, ignored, testFn)
+    adapter().test(name, ignored, testFn)
 }
 
-internal var currentAdapter: FrameworkAdapter = TeamcityAdapter()
+internal var currentAdapter: FrameworkAdapter? = null
+
+@JsFun("() => typeof describe === 'function' && typeof it === 'function'")
+private external fun isJasmine(): Boolean
+
+internal fun adapter(): FrameworkAdapter {
+    val result = currentAdapter ?: if (isJasmine()) JasmineLikeAdapter() else TeamcityAdapter()
+    currentAdapter = result
+    return result
+}
 
 // This is called from the js-launcher alongside wasm start function
 @JsExport