fix conflicting aliases producing random results because of map usage

analyzer.go

@@ -13,7 +13,7 @@ import (
 )
 
 var config = &Config{
-	RequiredAlias: make(map[string]string),
+	RequiredAlias: make([][]string, 0),
 }
 
 var Analyzer = &analysis.Analyzer{

analyzer_test.go

@@ -16,7 +16,7 @@ import (
 
 func makeAnalyzer() *analysis.Analyzer {
 	cnf := Config{
-		RequiredAlias: make(map[string]string),
+		RequiredAlias: make([][]string, 0),
 	}
 	return &analysis.Analyzer{
 		Name:  "importas",
@@ -43,9 +43,9 @@ func TestIncorrectFlags(t *testing.T) {
 }
 
 func TestConcurrency(t *testing.T) {
-	aliases := stringMap{
-		"fmt": "fff",
-		"os":  "stdos",
+	aliases := aliasList{
+		[]string{"fmt", "fff"},
+		[]string{"os", "stdos"},
 	}
 	testdata := analysistest.TestData()
 	dir := filepath.Join(testdata, "src", "b")
@@ -64,8 +64,8 @@ func TestConcurrency(t *testing.T) {
 	}
 	a := makeAnalyzer()
 	flg := a.Flags.Lookup("alias")
-	for k, v := range aliases {
-		err := flg.Value.Set(fmt.Sprintf("%s:%s", k, v))
+	for _, alias := range aliases {
+		err := flg.Value.Set(fmt.Sprintf("%s:%s", alias[0], alias[1]))
 		if err != nil {
 			t.Fatal(err)
 		}
@@ -100,49 +100,49 @@ func TestAnalyzer(t *testing.T) {
 	testCases := []struct {
 		desc                 string
 		pkg                  string
-		aliases              stringMap
+		aliases              aliasList
 		disallowUnaliased    bool
 		disallowExtraAliases bool
 	}{
 		{
 			desc: "Invalid imports",
 			pkg:  "a",
-			aliases: stringMap{
-				"fmt": "fff",
-				"os":  "stdos",
-				"io":  "iio",
+			aliases: aliasList{
+				[]string{"fmt", "fff"},
+				[]string{"os", "stdos"},
+				[]string{"io", "iio"},
 			},
 		},
 		{
 			desc: "Valid imports",
 			pkg:  "b",
-			aliases: stringMap{
-				"fmt": "fff",
-				"os":  "stdos",
+			aliases: aliasList{
+				[]string{"fmt", "fff"},
+				[]string{"os", "stdos"},
 			},
 		},
 		{
 			desc: "external libs",
 			pkg:  "c",
-			aliases: stringMap{
-				"knative.dev/serving/pkg/apis/autoscaling/v1alpha1": "autoscalingv1alpha1",
-				"knative.dev/serving/pkg/apis/serving/v1":           "servingv1",
+			aliases: aliasList{
+				[]string{"knative.dev/serving/pkg/apis/autoscaling/v1alpha1", "autoscalingv1alpha1"},
+				[]string{"knative.dev/serving/pkg/apis/serving/v1", "servingv1"},
 			},
 		},
 		{
 			desc: "regexp",
 			pkg:  "d",
-			aliases: stringMap{
-				"knative.dev/serving/pkg/apis/(\\w+)/(v[\\w\\d]+)": "$1$2",
+			aliases: aliasList{
+				[]string{"knative.dev/serving/pkg/apis/(\\w+)/(v[\\w\\d]+)", "$1$2"},
 			},
 		},
 		{
 			desc: "disallow unaliased mode",
 			pkg:  "e",
-			aliases: stringMap{
-				"fmt": "fff",
-				"os":  "stdos",
-				"io":  "iio",
+			aliases: aliasList{
+				[]string{"fmt", "fff"},
+				[]string{"os", "stdos"},
+				[]string{"io", "iio"},
 			},
 			disallowUnaliased: true,
 		},
@@ -154,18 +154,26 @@ func TestAnalyzer(t *testing.T) {
 		{
 			desc: "regexp with non capturing groups",
 			pkg:  "g",
-			aliases: stringMap{
-				"knative.dev/serving/pkg/(?:apis/)?(\\w+)(?:/v[\\w\\d]+)?": "k$1",
+			aliases: aliasList{
+				[]string{"knative.dev/serving/pkg/(?:apis/)?(\\w+)(?:/v[\\w\\d]+)?", "k$1"},
 			},
 		},
 		{
 			desc: "dot imports should be handled correctly",
 			pkg:  "h",
-			aliases: stringMap{
-				"github.com/onsi/gomega": ".",
+			aliases: aliasList{
+				[]string{"github.com/onsi/gomega", "."},
 			},
 			disallowUnaliased: true,
 		},
+		{
+			desc: "conflicting aliases",
+			pkg:  "i",
+			aliases: aliasList{
+				[]string{"knative.dev/serving/pkg/apis/serving/v1", "special"}, // this goes first
+				[]string{"knative.dev/serving/pkg/apis/(\\w+)/(v[\\w\\d]+)", "$1$2"},
+			},
+		},
 	}
 
 	for _, test := range testCases {
@@ -189,8 +197,8 @@ func TestAnalyzer(t *testing.T) {
 			}
 			a := makeAnalyzer()
 			flg := a.Flags.Lookup("alias")
-			for k, v := range test.aliases {
-				err := flg.Value.Set(fmt.Sprintf("%s:%s", k, v))
+			for _, alias := range test.aliases {
+				err := flg.Value.Set(fmt.Sprintf("%s:%s", alias[0], alias[1]))
 				if err != nil {
 					t.Fatal(err)
 				}

config.go

@@ -8,7 +8,7 @@ import (
 )
 
 type Config struct {
-	RequiredAlias        map[string]string
+	RequiredAlias        aliasList
 	Rules                []*Rule
 	DisallowUnaliased    bool
 	DisallowExtraAliases bool
@@ -22,7 +22,8 @@ func (c *Config) CompileRegexp() error {
 		return nil
 	}
 	rules := make([]*Rule, 0, len(c.RequiredAlias))
-	for path, alias := range c.RequiredAlias {
+	for _, aliases := range c.RequiredAlias {
+		path, alias := aliases[0], aliases[1]
 		reg, err := regexp.Compile(fmt.Sprintf("^%s$", path))
 		if err != nil {
 			return err

flags.go

@@ -11,23 +11,23 @@ var errWrongAlias = errors.New("import flag must be of form path:alias")
 
 func flags(config *Config) flag.FlagSet {
 	fs := flag.FlagSet{}
-	fs.Var(stringMap(config.RequiredAlias), "alias", "required import alias in form path:alias")
+	fs.Var(&config.RequiredAlias, "alias", "required import alias in form path:alias")
 	fs.BoolVar(&config.DisallowUnaliased, "no-unaliased", false, "do not allow unaliased imports of aliased packages")
 	fs.BoolVar(&config.DisallowExtraAliases, "no-extra-aliases", false, "do not allow non-required aliases")
 	return fs
 }
 
-type stringMap map[string]string
+type aliasList [][]string
 
-func (v stringMap) Set(val string) error {
+func (v *aliasList) Set(val string) error {
 	lastColon := strings.LastIndex(val, ":")
 	if lastColon <= 1 {
 		return errWrongAlias
 	}
-	v[val[:lastColon]] = val[lastColon+1:]
+	*v = append(*v, []string{val[:lastColon], val[lastColon+1:]})
 	return nil
 }
 
-func (v stringMap) String() string {
-	return fmt.Sprintf("%v", (map[string]string)(v))
+func (v *aliasList) String() string {
+	return fmt.Sprintf("%v", ([][]string)(*v))
 }

testdata/src/i/go.mod

@@ -0,0 +1,5 @@
+module github.com/julz/importas/testdata/src/d
+
+go 1.15
+
+require knative.dev/serving v0.21.0