Fix issue with custom types shadowing basic types (#163)

When a custom type has a name that can shadow an in-built type, append
MoqParam to the name. Example: var name stringMoqParam for null.String.

internal/registry/var.go

@@ -49,7 +49,12 @@ func varName(vr *types.Var, suffix string) string {
 	switch name {
 	case "mock", "callInfo", "break", "default", "func", "interface", "select", "case", "defer", "go", "map", "struct",
 		"chan", "else", "goto", "package", "switch", "const", "fallthrough", "if", "range", "type", "continue", "for",
-		"import", "return", "var":
+		"import", "return", "var",
+		// avoid shadowing basic types
+		"string", "bool", "byte", "rune", "uintptr",
+		"int", "int8", "int16", "int32", "int64",
+		"uint", "uint8", "uint16", "uint32", "uint64",
+		"float32", "float64", "complex64", "complex128":
 		name += "MoqParam"
 	}
 

pkg/moq/moq_test.go

@@ -377,6 +377,12 @@ func TestMockGolden(t *testing.T) {
 			interfaces: []string{"Example"},
 			goldenFile: filepath.Join("testpackages/anonimport", "iface_moq.golden.go"),
 		},
+		{
+			name:       "ShadowTypes",
+			cfg:        Config{SrcDir: "testpackages/shadowtypes"},
+			interfaces: []string{"ShadowTypes"},
+			goldenFile: filepath.Join("testpackages/shadowtypes", "shadowtypes_moq.golden.go"),
+		},
 	}
 	for _, tc := range cases {
 		t.Run(tc.name, func(t *testing.T) {

pkg/moq/testpackages/shadowtypes/shadowtypes.go

@@ -0,0 +1,35 @@
+package shadowtypes
+
+import (
+	"github.com/matryer/moq/pkg/moq/testpackages/shadowtypes/types"
+)
+
+type ShadowTypes interface {
+	ShadowString(string, types.String)
+
+	ShadowInt(int, types.Int)
+	ShadowInt8(int8, types.Int8)
+	ShadowInt16(int16, types.Int16)
+	ShadowInt32(int32, types.Int32)
+	ShadowInt64(int64, types.Int64)
+
+	ShadowUint(uint, types.Uint)
+	ShadowUint8(uint8, types.Uint8)
+	ShadowUint16(uint16, types.Uint16)
+	ShadowUint32(uint32, types.Uint32)
+	ShadowUint64(uint64, types.Uint64)
+
+	ShadowFloat32(float32, types.Float32)
+	ShadowFloat64(float64, types.Float64)
+
+	ShadowByte(byte, types.Byte)
+
+	ShadowRune(rune, types.Rune)
+
+	ShadowBool(bool, types.Bool)
+
+	ShadowComplex64(complex64, types.Complex64)
+	ShadowComplex128(complex128, types.Complex128)
+
+	ShadowUintptr(uintptr, types.Uintptr)
+}