From 441cd3fd868da475456ab59cd7239396623d6137 Mon Sep 17 00:00:00 2001
From: Roman Mohr <rmohr@google.com>
Date: Thu, 3 Aug 2023 13:50:11 +0200
Subject: [PATCH] Properly handle dot imports

Typically no dot imports are desired but ginkgo/gomega is a common
exception.

Signed-off-by: Roman Mohr <rmohr@google.com>
---
 analyzer.go                | 14 +++++++++++---
 analyzer_test.go           | 10 ++++++++++
 testdata/src/h/go.mod      | 12 ++++++++++++
 testdata/src/h/go.sum      | 15 +++++++++++++++
 testdata/src/h/h.go        | 11 +++++++++++
 testdata/src/h/h.go.golden | 11 +++++++++++
 6 files changed, 70 insertions(+), 3 deletions(-)
 create mode 100644 testdata/src/h/go.mod
 create mode 100644 testdata/src/h/go.sum
 create mode 100644 testdata/src/h/h.go
 create mode 100644 testdata/src/h/h.go.golden

diff --git a/analyzer.go b/analyzer.go
index f196534..a1272b9 100644
--- a/analyzer.go
+++ b/analyzer.go
@@ -129,11 +129,19 @@ func findEdits(node ast.Node, uses map[*ast.Ident]types.Object, importPath, orig
 			// skip identifiers pointing to a different import statement.
 			continue
 		}
+		pos := use.Pos()
+		end := use.End()
+		replacement := packageReplacement
+
+		if packageReplacement == "." {
+			replacement = ""
+			end = end + 1
+		}
 
 		result = append(result, analysis.TextEdit{
-			Pos:     use.Pos(),
-			End:     use.End(),
-			NewText: []byte(packageReplacement),
+			Pos:     pos,
+			End:     end,
+			NewText: []byte(replacement),
 		})
 	}
 
diff --git a/analyzer_test.go b/analyzer_test.go
index 0329ad9..6a339aa 100644
--- a/analyzer_test.go
+++ b/analyzer_test.go
@@ -18,6 +18,8 @@ func makeAnalyzer() *analysis.Analyzer {
 		RequiredAlias: make(map[string]string),
 	}
 	return &analysis.Analyzer{
+		Name:  "importas",
+		Doc:   "something",
 		Flags: flags(&cnf),
 		Run: func(pass *analysis.Pass) (interface{}, error) {
 			return runWithConfig(&cnf, pass)
@@ -103,6 +105,14 @@ func TestAnalyzer(t *testing.T) {
 				"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": ".",
+			},
+			disallowUnaliased: true,
+		},
 	}
 
 	for _, test := range testCases {
diff --git a/testdata/src/h/go.mod b/testdata/src/h/go.mod
new file mode 100644
index 0000000..1da964e
--- /dev/null
+++ b/testdata/src/h/go.mod
@@ -0,0 +1,12 @@
+module github.com/julz/importas/testdata/src/h
+
+go 1.20
+
+require github.com/onsi/gomega v1.24.1
+
+require (
+	github.com/google/go-cmp v0.5.9 // indirect
+	golang.org/x/net v0.2.0 // indirect
+	golang.org/x/text v0.4.0 // indirect
+	gopkg.in/yaml.v3 v3.0.1 // indirect
+)
diff --git a/testdata/src/h/go.sum b/testdata/src/h/go.sum
new file mode 100644
index 0000000..a3d1dba
--- /dev/null
+++ b/testdata/src/h/go.sum
@@ -0,0 +1,15 @@
+github.com/go-logr/logr v1.2.3 h1:2DntVwHkVopvECVRSlL5PSo9eG+cAkDCuckLubN+rq0=
+github.com/google/go-cmp v0.5.9 h1:O2Tfq5qg4qc4AmwVlvv0oLiVAGB7enBSJ2x2DqQFi38=
+github.com/google/go-cmp v0.5.9/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/onsi/ginkgo/v2 v2.5.0 h1:TRtrvv2vdQqzkwrQ1ke6vtXf7IK34RBUJafIy1wMwls=
+github.com/onsi/gomega v1.24.1 h1:KORJXNNTzJXzu4ScJWssJfJMnJ+2QJqhoQSRwNlze9E=
+github.com/onsi/gomega v1.24.1/go.mod h1:3AOiACssS3/MajrniINInwbfOOtfZvplPzuRSmvt1jM=
+golang.org/x/net v0.2.0 h1:sZfSu1wtKLGlWI4ZZayP0ck9Y73K1ynO6gqzTdBVdPU=
+golang.org/x/net v0.2.0/go.mod h1:KqCZLdyyvdV855qA2rE3GC2aiw5xGR5TEjj8smXukLY=
+golang.org/x/sys v0.2.0 h1:ljd4t30dBnAvMZaQCevtY0xLLD0A+bRZXbgLMLU1F/A=
+golang.org/x/text v0.4.0 h1:BrVqGRd7+k1DiOgtnFvAkoQEWQvBc25ouMJM6429SFg=
+golang.org/x/text v0.4.0/go.mod h1:mrYo+phRRbMaCq/xk9113O4dZlRixOauAjOtrjsXDZ8=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405 h1:yhCVgyC4o1eVCa2tZl7eS0r+SDo693bJlVdllGtEeKM=
+gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
+gopkg.in/yaml.v3 v3.0.1 h1:fxVm/GzAzEWqLHuvctI91KS9hhNmmWOoWu0XTYJS7CA=
+gopkg.in/yaml.v3 v3.0.1/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
diff --git a/testdata/src/h/h.go b/testdata/src/h/h.go
new file mode 100644
index 0000000..739af35
--- /dev/null
+++ b/testdata/src/h/h.go
@@ -0,0 +1,11 @@
+package h
+
+import (
+	"github.com/onsi/gomega" // want `import "github.com/onsi/gomega" imported without alias but must be with alias "." according to config`
+)
+
+func foo() {
+	gomega.Expect(nil).To(gomega.BeNil())
+	gomega.
+		Expect(true).To(gomega.BeTrue())
+}
diff --git a/testdata/src/h/h.go.golden b/testdata/src/h/h.go.golden
new file mode 100644
index 0000000..c44a00d
--- /dev/null
+++ b/testdata/src/h/h.go.golden
@@ -0,0 +1,11 @@
+package h
+
+import (
+	. "github.com/onsi/gomega" // want `import "github.com/onsi/gomega" imported without alias but must be with alias "." according to config`
+)
+
+func foo() {
+	Expect(nil).To(BeNil())
+
+	Expect(true).To(BeTrue())
+}