Add tests for insensitive variants of filter methods

internal/filter/filter_test.go

@@ -279,6 +279,33 @@ func ExampleList() {
 	// match: true
 }
 
+var filterInsensitiveListTests = []struct {
+	patterns []string
+	path     string
+	match    bool
+}{
+	{[]string{"*.go"}, "/foo/bar/test.go", true},
+	{[]string{"test.go"}, "/foo/bar/test.go", true},
+	{[]string{"test.go"}, "/foo/bar/TEST.go", true},
+	{[]string{"BAR"}, "/foo/BAR/TEST.go", true},
+}
+
+func TestInsensitiveList(t *testing.T) {
+	for i, test := range filterInsensitiveListTests {
+		match, _, err := filter.InsensitiveList(test.patterns, test.path)
+		if err != nil {
+			t.Errorf("test %d failed: expected no error for patterns %q, but error returned: %v",
+				i, test.patterns, err)
+			continue
+		}
+
+		if match != test.match {
+			t.Errorf("test %d: filter.InsensitiveList(%q, %q): expected %v, got %v",
+				i, test.patterns, test.path, test.match, match)
+		}
+	}
+}
+
 func extractTestLines(t testing.TB) (lines []string) {
 	f, err := os.Open("testdata/libreoffice.txt.bz2")
 	if err != nil {