Fix outputType struct tag for VirtualColumn expressions (#51)

* exclude examples from build

* fix outputType on expressions

Co-authored-by: Shrivardhan Rao <[email protected]>

builder/virtualcolumn/expression.go

@@ -1,19 +1,12 @@
 package virtualcolumn
 
-type OutputType string
-
-const (
-	Long   OutputType = "LONG"
-	Float             = "FLOAT"
-	Double            = "DOUBLE"
-	String            = "STRING"
-)
+import "github.com/grafadruid/go-druid/builder/types"
 
 type Expression struct {
 	Base
-	Name       string `json:"name,omitempty"`
-	Expression string `json:"expression,omitempty"`
-	OutputType OutputType
+	Name       string           `json:"name,omitempty"`
+	Expression string           `json:"expression,omitempty"`
+	OutputType types.OutputType `json:"outputType,omitempty"`
 }
 
 func NewExpression() *Expression {
@@ -32,7 +25,7 @@ func (e *Expression) SetExpression(expression string) *Expression {
 	return e
 }
 
-func (e *Expression) SetOutputType(outputType OutputType) *Expression {
+func (e *Expression) SetOutputType(outputType types.OutputType) *Expression {
 	e.OutputType = outputType
 	return e
 }

builder/virtualcolumn/expression_test.go

@@ -0,0 +1,19 @@
+package virtualcolumn
+
+import (
+	"encoding/json"
+	"github.com/grafadruid/go-druid/builder/types"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func TestNewExpression(t *testing.T) {
+	expression := NewExpression()
+	expression.SetName("dim1").SetExpression("lower(\"dim1\")").SetOutputType(types.String)
+
+	expected := `{"type":"expression", "name":"dim1", "expression": "lower(\"dim1\")", "outputType":"STRING"}`
+
+	expressionJSON, err := json.Marshal(expression)
+	assert.Nil(t, err)
+	assert.JSONEq(t, expected, string(expressionJSON))
+}

examples/fromjson/main.go

@@ -1,3 +1,5 @@
+//+build mage
+
 package main
 
 import (

examples/main.go

@@ -1,3 +1,5 @@
+//+build mage
+
 package main
 
 import (

examples/tdigestExample.go

@@ -1,3 +1,5 @@
+//+build mage
+
 package main
 
 import (