wasm test suite (#1116)

* wasm: add test suite using headlless chrome

tests/wasm/fmtprint_test.go

@@ -0,0 +1,39 @@
+// +build go1.14
+
+package wasm
+
+import (
+	"testing"
+	"time"
+
+	"github.com/chromedp/chromedp"
+)
+
+func TestFmtprint(t *testing.T) {
+
+	t.Parallel()
+
+	err := run("tinygo build -o " + wasmTmpDir + "/fmtprint.wasm -target wasm testdata/fmtprint.go")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	ctx, cancel := chromectx(5 * time.Second)
+	defer cancel()
+
+	var log1 string
+	err = chromedp.Run(ctx,
+		chromedp.Navigate("http://localhost:8826/run?file=fmtprint.wasm"),
+		chromedp.Sleep(time.Second),
+		chromedp.InnerHTML("#log", &log1),
+		waitLog(`test from fmtprint 1
+test from fmtprint 2
+test from fmtprint 3
+test from fmtprint 4`),
+	)
+	t.Logf("log1: %s", log1)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+}