Add tests for context funcs

logr_test.go

@@ -0,0 +1,76 @@
+/*
+Copyright 2021 The logr Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package logr
+
+import (
+	"context"
+	"testing"
+)
+
+// testLogger is a Logger just for testing that does nothing.
+type testLogger struct{}
+
+func (l *testLogger) Enabled() bool {
+	return false
+}
+
+func (l *testLogger) Info(msg string, keysAndValues ...interface{}) {
+}
+
+func (l *testLogger) Error(err error, msg string, keysAndValues ...interface{}) {
+}
+
+func (l *testLogger) V(level int) Logger {
+	return l
+}
+
+func (l *testLogger) WithValues(keysAndValues ...interface{}) Logger {
+	return l
+}
+
+func (l *testLogger) WithName(name string) Logger {
+	return l
+}
+
+// Verify that it actually implements the interface
+var _ Logger = &testLogger{}
+
+func TestContext(t *testing.T) {
+	ctx := context.TODO()
+
+	if out := FromContext(ctx); out != nil {
+		t.Errorf("expected nil logger, got %#v", out)
+	}
+	if out := FromContextOrDiscard(ctx); out == nil {
+		t.Errorf("expected non-nil logger")
+	} else if _, ok := out.(discardLogger); !ok {
+		t.Errorf("expected a discardLogger, got %#v", out)
+	}
+
+	logger := &testLogger{}
+	lctx := NewContext(ctx, logger)
+	if out := FromContext(lctx); out == nil {
+		t.Errorf("expected non-nil logger")
+	} else if out.(*testLogger) != logger {
+		t.Errorf("expected output to be the same as input: got in=%p, out=%p", logger, out)
+	}
+	if out := FromContextOrDiscard(lctx); out == nil {
+		t.Errorf("expected non-nil logger")
+	} else if out.(*testLogger) != logger {
+		t.Errorf("expected output to be the same as input: got in=%p, out=%p", logger, out)
+	}
+}