Add more tests

Author: amarziali

internal-api/src/test/groovy/datadog/trace/api/MethodFilterConfigParserTest.groovy

@@ -46,6 +46,27 @@ class MethodFilterConfigParserTest extends DDSpecification {
     "asdfg;c1[m1]"                                                  | [:]
   }
 
+  def "test native method configuration \"#value\""() {
+    setup:
+    if (value) {
+      injectSysConfig("dd.trace.native.methods", value)
+    } else {
+      removeSysConfig("dd.trace.methods")
+    }
+
+    expect:
+    InstrumenterConfig.get().traceNativeMethods == expected
+
+    where:
+    value                      | expected
+    null                       | [:]
+    " "                        | [:]
+    "*"                        | [:]
+    "[ method , ]"             | ["": ["method"].toSet()]
+    "lib[ method1 ,  method2]" | ["lib": ["method1", "method2"].toSet()]
+    "[*]"                      | ["": ["*"].toSet()]
+  }
+
   def "survive very long list"() {
     setup:
     def mset = ["m1", "m2"].toSet()