test: add importShadow test

Author: ldez

pkg/golinters/gocritic/testdata/gocritic_importShadow.go

@@ -0,0 +1,17 @@
+//golangcitest:args -Egocritic
+//golangcitest:config_path testdata/gocritic_inportShadow.yml
+package testdata
+
+import (
+	"fmt"
+	"path/filepath"
+)
+
+func Bar() {
+	filepath.Join("a", "b")
+}
+
+func foo() {
+	filepath := "foo.txt" // want "importShadow: shadow of imported package 'filepath'"
+	fmt.Printf("File path: %s\n", filepath)
+}

pkg/golinters/gocritic/testdata/gocritic_inportShadow.yml

@@ -0,0 +1,8 @@
+version: "2"
+
+linters:
+  settings:
+    gocritic:
+      disable-all: true
+      enabled-checks:
+        - importShadow