Add sql nullable types. (#46)

* Add sql nullable types.

README.md

@@ -19,18 +19,27 @@ I took the output of the [Stringer](https://godoc.org/golang.org/x/tools/cmd/str
 
 ``` shell
 go-enum --help
-Options:
-
-  -h, --help       display help information
-  -f, --file      *The file(s) to generate enums.  Use more than one flag for more files.
-      --noprefix   Prevents the constants generated from having the Enum as a prefix.
-      --lower      Adds lowercase variants of the enum strings for lookup.
-      --marshal    Adds text (and inherently json) marshalling functions.
-      --sql        Adds SQL database scan and value functions.
-      --flag       Adds golang flag functions.
-      --prefix     Replaces the prefix with a user one.
-      --names      Generates a 'Names() []string' function, and adds the possible enum values in the error response during parsing
-      --nocamel    Removes the snake_case to CamelCase name changing
+NAME:
+   go-enum - An enum generator for go
+
+USAGE:
+   go-enum [global options] [arguments...]
+
+GLOBAL OPTIONS:
+   --file value, -f value  The file(s) to generate enums.  Use more than one flag for more files.
+   --noprefix              Prevents the constants generated from having the Enum as a prefix. (default: false)
+   --lower                 Adds lowercase variants of the enum strings for lookup. (default: false)
+   --nocase                Adds case insensitive parsing to the enumeration (forces lower flag). (default: false)
+   --marshal               Adds text (and inherently json) marshalling functions. (default: false)
+   --sql                   Adds SQL database scan and value functions. (default: false)
+   --flag                  Adds golang flag functions. (default: false)
+   --prefix value          Replaces the prefix with a user one.
+   --names                 Generates a 'Names() []string' function, and adds the possible enum values in the error response during parsing (default: false)
+   --nocamel               Removes the snake_case to CamelCase name changing (default: false)
+   --ptr                   Adds a pointer method to get a pointer from const values (default: false)
+   --sqlnullint            Adds a Null{{ENUM}} type for marshalling a nullable int value to sql (default: false)
+   --sqlnullstr            Adds a Null{{ENUM}} type for marshalling a nullable string value to sql.  If sqlnullint is specified too, it will be Null{{ENUM}}Str (default: false)
+   --help, -h              show help (default: false)
 ```
 
 ### Syntax

example/color.go

@@ -1,4 +1,4 @@
-//go:generate ../bin/go-enum -f=$GOFILE --marshal --lower
+//go:generate ../bin/go-enum -f=$GOFILE --marshal --lower --ptr
 
 package example
 

example/color_test.go

@@ -3,6 +3,7 @@ package example
 import (
 	"encoding/json"
 	"errors"
+	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -19,6 +20,7 @@ func TestColorString(t *testing.T) {
 
 	assert.Equal(t, Color(33), ColorGreen)
 	assert.Equal(t, Color(34), ColorBlue)
+	assert.Equal(t, &x, Color(109).Ptr())
 }
 
 func TestColorUnmarshal(t *testing.T) {
@@ -225,3 +227,25 @@ func TestColorMarshal(t *testing.T) {
 		})
 	}
 }
+
+func BenchmarkColorParse(b *testing.B) {
+
+	knownItems := []string{
+		ColorRedOrangeBlue.String(),
+		strings.ToLower(ColorRedOrangeBlue.String()),
+		// "2",  Leave this in to add an int as string parsing option in future.
+	}
+
+	var err error
+	for _, item := range knownItems {
+		b.Run(item, func(b *testing.B) {
+			b.ReportAllocs()
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				_, err = ParseColor(item)
+				assert.NoError(b, err)
+			}
+		})
+	}
+
+}

example/example_test.go

@@ -5,6 +5,7 @@ import (
 	"errors"
 	"flag"
 	"fmt"
+	"strings"
 	"testing"
 
 	"github.com/spf13/pflag"
@@ -219,3 +220,57 @@ func TestNoZeroValues(t *testing.T) {
 
 	}
 }
+
+func BenchmarkMakeParse(b *testing.B) {
+
+	knownItems := map[string]struct {
+		input  string
+		output Make
+		err    error
+	}{
+		"cased lookup": {
+			input:  MakeAudi.String(),
+			output: MakeAudi,
+		},
+		"lowercase lookup": {
+			input:  strings.ToLower(MakeVolkswagon.String()),
+			output: MakeVolkswagon,
+		},
+		"hyphenated upper": {
+			input:  strings.ToUpper(MakeMercedesBenz.String()),
+			output: MakeMercedesBenz,
+		},
+		// Leave this in to add an int as string parsing option in future.
+		// "numeric": {
+		// 	input:  "2",
+		// 	output: MakeChevy,
+		// },
+		// "last numeric": {
+		// 	input:  "20",
+		// 	output: MakeVolkswagon,
+		// },
+		"failure": {
+			input:  "xyz",
+			output: MakeToyota,
+			err:    errors.New("xyz is not a valid Make, try [Toyota, Chevy, Ford, Tesla, Hyundai, Nissan, Jaguar, Audi, BMW, Mercedes-Benz, Volkswagon]"),
+		},
+	}
+
+	for name, tc := range knownItems {
+		b.Run(name, func(b *testing.B) {
+			b.ReportAllocs()
+
+			b.ResetTimer()
+			for i := 0; i < b.N; i++ {
+				out, err := ParseMake(tc.input)
+				assert.Equal(b, tc.output, out)
+				if tc.err != nil {
+					assert.Error(b, err)
+				} else {
+					assert.NoError(b, err)
+				}
+			}
+		})
+	}
+
+}

example/sql.go

@@ -1,4 +1,4 @@
-//go:generate ../bin/go-enum -f=$GOFILE --sql
+//go:generate ../bin/go-enum -f=$GOFILE --sql --sqlnullstr --sqlnullint --ptr --marshal
 
 package example