From 24883c20a6ff09bf1822a8c9f8c5e29a8554de9a Mon Sep 17 00:00:00 2001
From: Suhas Karanth <sudo-suhas@users.noreply.github.com>
Date: Sun, 16 Aug 2020 12:16:52 +0530
Subject: [PATCH] Use fallback name for parameter when name is _ (#131)

---
 pkg/moq/moq.go                                |  2 +-
 pkg/moq/moq_test.go                           | 26 ++++++-
 pkg/moq/testpackages/blankid/swallower.go     |  5 ++
 .../testpackages/blankid/swallower.golden.go  | 73 +++++++++++++++++++
 .../variadic/{testdata => }/echoer.golden.go  |  0
 5 files changed, 103 insertions(+), 3 deletions(-)
 create mode 100644 pkg/moq/testpackages/blankid/swallower.go
 create mode 100644 pkg/moq/testpackages/blankid/swallower.golden.go
 rename pkg/moq/testpackages/variadic/{testdata => }/echoer.golden.go (100%)

diff --git a/pkg/moq/moq.go b/pkg/moq/moq.go
index d7ffe1e..0a10202 100644
--- a/pkg/moq/moq.go
+++ b/pkg/moq/moq.go
@@ -201,7 +201,7 @@ func (m *Mocker) extractArgs(sig *types.Signature) (params, results []*param) {
 
 func (m *Mocker) buildParam(v *types.Var, fallbackName string) *param {
 	name := v.Name()
-	if name == "" {
+	if name == "" || name == "_" {
 		name = fallbackName
 	}
 	typ := types.TypeString(v.Type(), m.packageQualifier)
diff --git a/pkg/moq/moq_test.go b/pkg/moq/moq_test.go
index 79eaa6c..2178e62 100644
--- a/pkg/moq/moq_test.go
+++ b/pkg/moq/moq_test.go
@@ -233,7 +233,26 @@ func TestSliceResult(t *testing.T) {
 		t.Errorf("m.Mock: %s", err)
 	}
 
-	golden := filepath.Join("testpackages/variadic/testdata", "echoer.golden.go")
+	golden := filepath.Join("testpackages/variadic", "echoer.golden.go")
+	if err := matchGoldenFile(golden, buf.Bytes()); err != nil {
+		t.Errorf("check golden file: %s", err)
+	}
+}
+
+// TestBlankID tests generation of mock where a method on the interface
+// uses a blank identifier.
+// See https://github.com/matryer/moq/issues/70
+func TestBlankID(t *testing.T) {
+	m, err := New(Config{SrcDir: "testpackages/blankid"})
+	if err != nil {
+		t.Fatalf("moq.New: %s", err)
+	}
+
+	var buf bytes.Buffer
+	if err = m.Mock(&buf, "Swallower"); err != nil {
+		t.Errorf("m.Mock: %s", err)
+	}
+	golden := filepath.Join("testpackages/blankid", "swallower.golden.go")
 	if err := matchGoldenFile(golden, buf.Bytes()); err != nil {
 		t.Errorf("check golden file: %s", err)
 	}
@@ -342,8 +361,11 @@ func matchGoldenFile(goldenFile string, actual []byte) error {
 	// To update golden files, run the following:
 	// go test -v -run '^<Test-Name>$' github.com/matryer/moq/pkg/moq -update
 	if *update {
+		if err := os.MkdirAll(filepath.Dir(goldenFile), 0755); err != nil {
+			return fmt.Errorf("create dir: %s", err)
+		}
 		if err := ioutil.WriteFile(goldenFile, actual, 0644); err != nil {
-			return fmt.Errorf("write: %s: %s", goldenFile, err)
+			return fmt.Errorf("write: %s", err)
 		}
 
 		return nil
diff --git a/pkg/moq/testpackages/blankid/swallower.go b/pkg/moq/testpackages/blankid/swallower.go
new file mode 100644
index 0000000..7d73d7b
--- /dev/null
+++ b/pkg/moq/testpackages/blankid/swallower.go
@@ -0,0 +1,5 @@
+package blankid
+
+type Swallower interface {
+	Swallow(_ string)
+}
diff --git a/pkg/moq/testpackages/blankid/swallower.golden.go b/pkg/moq/testpackages/blankid/swallower.golden.go
new file mode 100644
index 0000000..ecdcfa6
--- /dev/null
+++ b/pkg/moq/testpackages/blankid/swallower.golden.go
@@ -0,0 +1,73 @@
+// Code generated by moq; DO NOT EDIT.
+// github.com/matryer/moq
+
+package blankid
+
+import (
+	"sync"
+)
+
+// Ensure, that SwallowerMock does implement Swallower.
+// If this is not the case, regenerate this file with moq.
+var _ Swallower = &SwallowerMock{}
+
+// SwallowerMock is a mock implementation of Swallower.
+//
+//     func TestSomethingThatUsesSwallower(t *testing.T) {
+//
+//         // make and configure a mocked Swallower
+//         mockedSwallower := &SwallowerMock{
+//             SwallowFunc: func(in1 string)  {
+// 	               panic("mock out the Swallow method")
+//             },
+//         }
+//
+//         // use mockedSwallower in code that requires Swallower
+//         // and then make assertions.
+//
+//     }
+type SwallowerMock struct {
+	// SwallowFunc mocks the Swallow method.
+	SwallowFunc func(in1 string)
+
+	// calls tracks calls to the methods.
+	calls struct {
+		// Swallow holds details about calls to the Swallow method.
+		Swallow []struct {
+			// In1 is the in1 argument value.
+			In1 string
+		}
+	}
+	lockSwallow sync.RWMutex
+}
+
+// Swallow calls SwallowFunc.
+func (mock *SwallowerMock) Swallow(in1 string) {
+	if mock.SwallowFunc == nil {
+		panic("SwallowerMock.SwallowFunc: method is nil but Swallower.Swallow was just called")
+	}
+	callInfo := struct {
+		In1 string
+	}{
+		In1: in1,
+	}
+	mock.lockSwallow.Lock()
+	mock.calls.Swallow = append(mock.calls.Swallow, callInfo)
+	mock.lockSwallow.Unlock()
+	mock.SwallowFunc(in1)
+}
+
+// SwallowCalls gets all the calls that were made to Swallow.
+// Check the length with:
+//     len(mockedSwallower.SwallowCalls())
+func (mock *SwallowerMock) SwallowCalls() []struct {
+	In1 string
+} {
+	var calls []struct {
+		In1 string
+	}
+	mock.lockSwallow.RLock()
+	calls = mock.calls.Swallow
+	mock.lockSwallow.RUnlock()
+	return calls
+}
diff --git a/pkg/moq/testpackages/variadic/testdata/echoer.golden.go b/pkg/moq/testpackages/variadic/echoer.golden.go
similarity index 100%
rename from pkg/moq/testpackages/variadic/testdata/echoer.golden.go
rename to pkg/moq/testpackages/variadic/echoer.golden.go