add helper functions for popups in tests

pkg/integration/components/matcher.go

@@ -0,0 +1,35 @@
+package components
+
+// for making assertions on string values
+type matcher struct {
+	// e.g. "contains 'foo'"
+	name string
+	// returns a bool that says whether the test passed and if it returns false, it
+	// also returns a string of the error message
+	testFn func(string) (bool, string)
+	// this is printed when there's an error so that it's clear what the context of the assertion is
+	prefix string
+}
+
+func NewMatcher(name string, testFn func(string) (bool, string)) *matcher {
+	return &matcher{name: name, testFn: testFn}
+}
+
+func (self *matcher) test(value string) (bool, string) {
+	ok, message := self.testFn(value)
+	if ok {
+		return true, ""
+	}
+
+	if self.prefix != "" {
+		return false, self.prefix + " " + message
+	}
+
+	return false, message
+}
+
+func (self *matcher) context(prefix string) *matcher {
+	self.prefix = prefix
+
+	return self
+}