Merge pull request #25 from arran4/Custom

Custom output per type

Author: OneOfOne

.gitignore

@@ -1,6 +1,7 @@
-*.txt
-*.pprof
-cmap2/
-cache/
-debug
+/*.txt
+/*.pprof
+/cmap2/
+/cache/
+/debug
+/testdata/testmodel1/s2ts_gen_*.go
 /helpers.js

README.md

@@ -131,6 +131,18 @@ Args:
 
 ```
 
+## Advanced
+
+### Custom output per model
+
+```golang
+type CustomTypescript interface {
+	RenderCustomTypescript(w io.Writer) (err error)
+}
+```
+If your model implements a ```RenderCustomTypescript(w io.Writer) (err error)``` function it will inject what ever you 
+write to the writer at the end of the model. struct2ts will handle the first level of indenting for you.
+
 ## TODO
 
 * Use [xast](https://github.com/OneOfOne/xast) to skip reflection.

go.sum

@@ -2,9 +2,12 @@ github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc h1:cAKDfWh5Vpd
 github.com/alecthomas/template v0.0.0-20160405071501-a0175ee3bccc/go.mod h1:LOuyumcjzFXgccqObfd/Ljyb9UuFJ6TxHnclSeseNhc=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf h1:qet1QNfXsQxTZqLG4oE62mJzwPIB8+Tee4RNCL9ulrY=
 github.com/alecthomas/units v0.0.0-20151022065526-2efee857e7cf/go.mod h1:ybxpYRFXyAe+OPACYpWeL0wqObRcbAqCMya13uyzqw0=
+github.com/davecgh/go-spew v1.1.0 h1:ZDRjVQ15GmhC3fiQ8ni8+OwkZQO4DARzQgrnXU1Liz8=
 github.com/davecgh/go-spew v1.1.0/go.mod h1:J7Y8YcW2NihsgmVo/mv3lAwl/skON4iLHjSsI+c5H38=
+github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
+github.com/stretchr/testify v1.3.0 h1:TivCn/peBQ7UY8ooIcPgZFpTNSz0Q2U6UrFlUfqbe0Q=
 github.com/stretchr/testify v1.3.0/go.mod h1:M5WIy9Dh21IEIfnGCwXGc5bZfKNJtfHm1UVUgZn+9EI=
 golang.org/x/tools v0.0.0-20190213135902-6bedcd10978a h1:ncPOGSo3avrTTUKHvDmwoS5E5of95qqNwftSXoxX+Wk=
 golang.org/x/tools v0.0.0-20190213135902-6bedcd10978a/go.mod h1:n7NCudcB/nEzxVGmLbDWY5pfWTLqBcC2KZ6jyYvM4mQ=

struct.go

@@ -1,6 +1,7 @@
 package struct2ts
 
 import (
+	"errors"
 	"fmt"
 	"io"
 	"reflect"
@@ -57,10 +58,52 @@ func (s *Struct) RenderTo(opts *Options, w io.Writer) (err error) {
 		return
 	}
 
+	if err = s.RenderCustom(opts, w); err != nil {
+		return
+	}
+
 	_, err = fmt.Fprint(w, "}")
 	return
 }
 
+type CustomTypescript interface {
+	RenderCustomTypescript(w io.Writer) (err error)
+}
+
+func (s *Struct) RenderCustom(opts *Options, w io.Writer) (err error) {
+	ww := newTabScanner(w, opts.indents[1])
+	ctit := reflect.TypeOf((*CustomTypescript)(nil)).Elem()
+	var implementingType reflect.Type = nil
+	if s.t.Implements(ctit) {
+		implementingType = ctit
+	}
+	if reflect.PtrTo(s.t).Implements(ctit) {
+		implementingType = reflect.PtrTo(s.t)
+	}
+	if implementingType != nil {
+		m, ok := implementingType.MethodByName("RenderCustomTypescript")
+		if !ok {
+			return errors.New("couldn't get method RenderCustomTypescript")
+		}
+		_, err = fmt.Fprintf(ww, "\n")
+		o := reflect.New(s.t)
+		if implementingType.Kind() != reflect.Ptr {
+			o = o.Elem()
+		}
+		wv := reflect.ValueOf(ww)
+		r := m.Func.Call([]reflect.Value{o, wv})
+		if len(r) > 0 && !r[0].IsNil() {
+			switch r0t := r[0].Interface().(type) {
+			case error:
+				return r0t
+			}
+		}
+		_, err = fmt.Fprintf(w, "\n")
+	}
+
+	return
+}
+
 func (s *Struct) RenderFields(opts *Options, w io.Writer) (err error) {
 	for _, f := range s.Fields {
 		if err = f.RenderTopLevel(w, opts); err != nil {

tabscanner.go

@@ -0,0 +1,37 @@
+package struct2ts
+
+import "io"
+
+type tabScanner struct {
+	output io.Writer
+	tabs   []byte
+}
+
+func (ts *tabScanner) Write(bs []byte) (n int, err error) {
+	p := 0
+	var rn int
+	for pos, b := range bs {
+		switch b {
+		case '\n':
+			rn, err = ts.output.Write(bs[p : pos+1])
+			n += rn
+			if err != nil {
+				return
+			}
+			_, err = ts.output.Write(ts.tabs)
+			if err != nil {
+				return
+			}
+			p = pos + 1
+		}
+	}
+	rn, err = ts.output.Write(bs[p:])
+	return n + rn, err
+}
+
+func newTabScanner(w io.Writer, tabs string) io.Writer {
+	return &tabScanner{
+		output: w,
+		tabs:   []byte(tabs),
+	}
+}

tabscanner_test.go

@@ -0,0 +1,95 @@
+package struct2ts
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestTabScanner_Write(t *testing.T) {
+	tests := []struct {
+		Name  string
+		Input struct {
+			Tabs    string
+			Buffers []string
+		}
+		Expected struct {
+			Output string
+			n      *int
+		}
+	}{
+		{
+			"One new line mid string - one input, 3 spaces",
+			struct {
+				Tabs    string
+				Buffers []string
+			}{Tabs: "   ", Buffers: []string{"Hello how are you?\nI'm fine thanks!"}},
+			struct {
+				Output string
+				n      *int
+			}{Output: "Hello how are you?\n   I'm fine thanks!"},
+		},
+		{
+			"One new line end string - one input, 3 spaces",
+			struct {
+				Tabs    string
+				Buffers []string
+			}{Tabs: "   ", Buffers: []string{"Hello how are you?\n"}},
+			struct {
+				Output string
+				n      *int
+			}{Output: "Hello how are you?\n   "},
+		},
+		{
+			"One new line start string - one input, 3 spaces",
+			struct {
+				Tabs    string
+				Buffers []string
+			}{Tabs: "   ", Buffers: []string{"\nHello how are you?"}},
+			struct {
+				Output string
+				n      *int
+			}{Output: "\n   Hello how are you?"},
+		},
+		{
+			"empty string",
+			struct {
+				Tabs    string
+				Buffers []string
+			}{Tabs: "   ", Buffers: []string{""}},
+			struct {
+				Output string
+				n      *int
+			}{Output: ""},
+		},
+		{
+			"Just a new line",
+			struct {
+				Tabs    string
+				Buffers []string
+			}{Tabs: "   ", Buffers: []string{"\n"}},
+			struct {
+				Output string
+				n      *int
+			}{Output: "\n   "},
+		},
+	}
+	for _, test := range tests {
+		t.Run(test.Name, func(t *testing.T) {
+			outputBuffer := bytes.NewBuffer(nil)
+			ts := newTabScanner(outputBuffer, test.Input.Tabs)
+			for _, s := range test.Input.Buffers {
+				_, err := ts.Write([]byte(s))
+				if err != nil {
+					t.Error("Buffer write error", err)
+				}
+			}
+			if outputBuffer.String() != test.Expected.Output {
+				t.Log("Output buffer doesn't match. Got ")
+				t.Log(outputBuffer.String())
+				t.Log("expected")
+				t.Log(test.Expected.Output)
+				t.Fail()
+			}
+		})
+	}
+}

testdata/testmodel1/testmodel1.go

@@ -0,0 +1,28 @@
+package testmodel1
+
+import (
+	"fmt"
+	"io"
+)
+
+type Struct1 struct {
+	HasNoCustomInterface int
+}
+
+type Struct2 struct {
+	TotallyDoesHaveOneAsAPointer int
+}
+
+func (s *Struct2) RenderCustomTypescript(w io.Writer) (err error) {
+	fmt.Fprint(w, "// Custom Output!!!")
+	return nil
+}
+
+type Struct3 struct {
+	TotallyDoesHaveOne int
+}
+
+func (s Struct3) RenderCustomTypescript(w io.Writer) (err error) {
+	fmt.Fprint(w, "// Custom Output!!!")
+	return nil
+}

testdata/testmodel1/testmodel1.sh

@@ -0,0 +1,5 @@
+#!/bin/bash -Xe
+
+go run github.com/OneOfOne/struct2ts/cmd/struct2ts github.com/OneOfOne/struct2ts/testdata/testmodel1.Struct1
+go run github.com/OneOfOne/struct2ts/cmd/struct2ts github.com/OneOfOne/struct2ts/testdata/testmodel1.Struct2
+go run github.com/OneOfOne/struct2ts/cmd/struct2ts github.com/OneOfOne/struct2ts/testdata/testmodel1.Struct3