Fix handling of imports with multiple slashes

internal/analyzer/analyzer.go

@@ -49,7 +49,7 @@ func inspect(pass *analysis.Pass, node ast.Node, checkRE *regexp.Regexp, state *
 			if err != nil {
 				return true
 			}
-			if idx := strings.IndexByte(n, '/'); idx != -1 {
+			if idx := strings.LastIndexByte(n, '/'); idx != -1 {
 				n = n[idx+1:]
 			}
 			state.imports[n] = struct{}{}

internal/analyzer/analyzer_test.go

@@ -20,6 +20,10 @@ func TestAnalyzer(t *testing.T) {
 			dir:     "custompattern",
 			pattern: `.*`,
 		},
+		{
+			dir:     "defaultclient",
+			pattern: `^(DefaultClient|DefaultTransport)$`,
+		},
 	}
 
 	wd, err := os.Getwd()

testdata/defaultclient/src/a/a.go

@@ -0,0 +1,20 @@
+package a
+
+import (
+	"io"
+	"net/http"
+
+	"config"
+)
+
+var DefaultClient = &http.Client{}
+
+func reassignPattern() {
+	io.EOF = nil
+
+	config.DefaultClient = nil // want "reassigning variable"
+	DefaultClient = nil
+
+	http.DefaultClient = nil    // want "reassigning variable"
+	http.DefaultTransport = nil // want "reassigning variable"
+}

testdata/defaultclient/src/config/config.go

@@ -0,0 +1,5 @@
+package config
+
+import "net/http"
+
+var DefaultClient = &http.Client{}

testdata/defaults/src/a/a.go

@@ -11,6 +11,7 @@ import cc "c"
 import (
 	"d"
 	"d/e"
+	"d/e/f"
 )
 
 var st = struct {
@@ -26,6 +27,8 @@ func foo() {
 
 	e.ErrE = nil // want "reassigning variable"
 
+	f.ErrF = nil // want "reassigning variable"
+
 	io.EOF = nil // want "reassigning variable"
 
 	st.ErrSt = errors.New("foo")

testdata/defaults/src/d/e/f/f.go

@@ -0,0 +1,7 @@
+package f
+
+import "errors"
+
+var (
+	ErrF = errors.New("f")
+)