feat: allow existing logger from context (#898)

We should reuse an existing context logger if in test context.
This will allow test to setup act with a null logger to assert
log messages.

Co-authored-by: Markus Wolf <markus.wolf@new-work.se>

Co-authored-by: Markus Wolf <markus.wolf@new-work.se>

pkg/common/testflag.go

@@ -0,0 +1,20 @@
+package common
+
+import (
+	"context"
+)
+
+type testFlagContextKey string
+
+const testFlagContextKeyVal = testFlagContextKey("test-context")
+
+// TestContext returns whether the context has the test flag set
+func TestContext(ctx context.Context) bool {
+	val := ctx.Value(testFlagContextKeyVal)
+	return val != nil
+}
+
+// WithTextContext sets the test flag in the context
+func WithTestContext(ctx context.Context) context.Context {
+	return context.WithValue(ctx, testFlagContextKeyVal, true)
+}