Tests for file.go added

file_test.go

@@ -0,0 +1,28 @@
+package mail
+
+import "testing"
+
+// TestFile_SetGetHeader tests the set-/getHeader method of the File object
+func TestFile_SetGetHeader(t *testing.T) {
+	f := File{
+		Name:   "testfile.txt",
+		Header: make(map[string][]string),
+	}
+	f.setHeader(HeaderContentType, "text/plain")
+	fi, ok := f.getHeader(HeaderContentType)
+	if !ok {
+		t.Errorf("getHeader method of File did not return a value")
+		return
+	}
+	if fi != "text/plain" {
+		t.Errorf("getHeader returned wrong value. Expected: %s, got: %s", "text/plain", fi)
+	}
+	fi, ok = f.getHeader(HeaderContentTransferEnc)
+	if ok {
+		t.Errorf("getHeader method of File did return a value, but wasn't supposed to")
+		return
+	}
+	if fi != "" {
+		t.Errorf("getHeader returned wrong value. Expected: %s, got: %s", "", fi)
+	}
+}