Support a generator for composite literals

Author: moznion

generator/composite_literal.go

@@ -0,0 +1,82 @@
+package generator
+
+import (
+	"fmt"
+	"strings"
+)
+
+type compositeLiteralField struct {
+	key   string
+	value Statement
+}
+
+// CompositeLiteral represents a code generator for composite literal.
+// Please see also: https://golang.org/doc/effective_go.html#composite_literals
+type CompositeLiteral struct {
+	typ    string
+	fields []*compositeLiteralField
+}
+
+// NewCompositeLiteral returns a new `CompositeLiteral`.
+func NewCompositeLiteral(typ string) *CompositeLiteral {
+	return &CompositeLiteral{
+		typ: typ,
+	}
+}
+
+// AddField adds a field as `Statement` to `ComposeLiteral`.
+// This method returns a *new* `Struct`; it means this method acts as immutable.
+func (c *CompositeLiteral) AddField(key string, value Statement) *CompositeLiteral {
+	return &CompositeLiteral{
+		typ: c.typ,
+		fields: append(c.fields, &compositeLiteralField{
+			key:   key,
+			value: value,
+		}),
+	}
+}
+
+// AddFieldStr adds a field as string to `ComposeLiteral`.
+// This method returns a *new* `Struct`; it means this method acts as immutable.
+func (c *CompositeLiteral) AddFieldStr(key string, value string) *CompositeLiteral {
+	return &CompositeLiteral{
+		typ: c.typ,
+		fields: append(c.fields, &compositeLiteralField{
+			key:   key,
+			value: NewRawStatement(fmt.Sprintf(`"%s"`, value)),
+		}),
+	}
+}
+
+// AddFieldRaw adds a field as raw text to `ComposeLiteral`.
+// This method returns a *new* `Struct`; it means this method acts as immutable.
+func (c *CompositeLiteral) AddFieldRaw(key string, value interface{}) *CompositeLiteral {
+	return &CompositeLiteral{
+		typ: c.typ,
+		fields: append(c.fields, &compositeLiteralField{
+			key:   key,
+			value: NewRawStatement(fmt.Sprintf("%v", value)),
+		}),
+	}
+}
+
+// Generate generates composite literal block as golang code.
+func (c *CompositeLiteral) Generate(indentLevel int) (string, error) {
+	indent := buildIndent(indentLevel)
+	nextLevelIndent := buildIndent(indentLevel + 1)
+
+	stmt := fmt.Sprintf("%s%s{\n", indent, c.typ)
+	for _, field := range c.fields {
+		genValue, err := field.value.Generate(indentLevel + 1)
+		if err != nil {
+			return "", err
+		}
+
+		genValue = strings.TrimSpace(genValue)
+
+		stmt += fmt.Sprintf("%s%s: %s,\n", nextLevelIndent, field.key, genValue)
+	}
+	stmt += fmt.Sprintf("%s}\n", indent)
+
+	return stmt, nil
+}

generator/composite_literal_test.go

@@ -0,0 +1,61 @@
+package generator
+
+import (
+	"testing"
+
+	"github.com/moznion/gowrtr/internal/errmsg"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestShouldGenerateCompositeLiteralBeSuccess(t *testing.T) {
+	composeGenerator := NewCompositeLiteral("&Struct").
+		AddField("foo", NewRawStatement(`"foo-value"`)).
+		AddFieldStr("bar", "bar-value").
+		AddField("buz", NewAnonymousFunc(
+			false,
+			NewAnonymousFuncSignature().ReturnTypes("bool"),
+			NewReturnStatement("true"),
+		).Invocation(NewFuncInvocation())).
+		AddFieldRaw("qux", 12345).
+		AddFieldRaw("foobar", false)
+
+	{
+		gen, err := composeGenerator.Generate(0)
+
+		assert.NoError(t, err)
+		expected := `&Struct{
+	foo: "foo-value",
+	bar: "bar-value",
+	buz: func() bool {
+		return true
+	}(),
+	qux: 12345,
+	foobar: false,
+}
+`
+		assert.Equal(t, expected, gen)
+	}
+
+	{
+		gen, err := composeGenerator.Generate(2)
+
+		assert.NoError(t, err)
+		expected := `		&Struct{
+			foo: "foo-value",
+			bar: "bar-value",
+			buz: func() bool {
+				return true
+			}(),
+			qux: 12345,
+			foobar: false,
+		}
+`
+		assert.Equal(t, expected, gen)
+	}
+}
+
+func TestShouldGenerateCompositeLiteralRaiseError(t *testing.T) {
+	_, err := NewCompositeLiteral("").AddField("foo", NewIf("")).Generate(0)
+	assert.EqualError(t, err, errmsg.IfConditionIsEmptyError().Error())
+}