refactoring: moved compare dashboard version command out of sqlstore, the code in this command did not use any sql operations and was more high level, could be moved out and use existing queries to get the versions

pkg/components/dashdiffs/compare.go

@@ -0,0 +1,124 @@
+package dashdiffs
+
+import (
+	"encoding/json"
+	"errors"
+
+	"github.com/grafana/grafana/pkg/bus"
+	"github.com/grafana/grafana/pkg/components/simplejson"
+	"github.com/grafana/grafana/pkg/models"
+	diff "github.com/yudai/gojsondiff"
+	deltaFormatter "github.com/yudai/gojsondiff/formatter"
+)
+
+type DiffType int
+
+const (
+	DiffJSON DiffType = iota
+	DiffBasic
+	DiffDelta
+)
+
+var (
+	// ErrUnsupportedDiffType occurs when an invalid diff type is used.
+	ErrUnsupportedDiffType = errors.New("dashdiff: unsupported diff type")
+
+	// ErrNilDiff occurs when two compared interfaces are identical.
+	ErrNilDiff = errors.New("dashdiff: diff is nil")
+)
+
+type Options struct {
+	OrgId       int64
+	DashboardId int64
+	BaseVersion int
+	NewVersion  int
+	DiffType    DiffType
+}
+
+type Result struct {
+	Delta []byte `json:"delta"`
+}
+
+// CompareDashboardVersionsCommand computes the JSON diff of two versions,
+// assigning the delta of the diff to the `Delta` field.
+func GetVersionDiff(options *Options) (*Result, error) {
+	baseVersionQuery := models.GetDashboardVersionQuery{
+		DashboardId: options.DashboardId,
+		Version:     options.BaseVersion,
+	}
+
+	if err := bus.Dispatch(&baseVersionQuery); err != nil {
+		return nil, err
+	}
+
+	newVersionQuery := models.GetDashboardVersionQuery{
+		DashboardId: options.DashboardId,
+		Version:     options.NewVersion,
+	}
+
+	if err := bus.Dispatch(&newVersionQuery); err != nil {
+		return nil, err
+	}
+
+	left, jsonDiff, err := getDiff(baseVersionQuery.Result, newVersionQuery.Result)
+	if err != nil {
+		return nil, err
+	}
+
+	result := &Result{}
+
+	switch options.DiffType {
+	case DiffDelta:
+
+		deltaOutput, err := deltaFormatter.NewDeltaFormatter().Format(jsonDiff)
+		if err != nil {
+			return nil, err
+		}
+		result.Delta = []byte(deltaOutput)
+
+	case DiffJSON:
+		jsonOutput, err := NewJSONFormatter(left).Format(jsonDiff)
+		if err != nil {
+			return nil, err
+		}
+		result.Delta = []byte(jsonOutput)
+
+	case DiffBasic:
+		basicOutput, err := NewBasicFormatter(left).Format(jsonDiff)
+		if err != nil {
+			return nil, err
+		}
+		result.Delta = basicOutput
+
+	default:
+		return nil, ErrUnsupportedDiffType
+	}
+
+	return result, nil
+}
+
+// getDiff computes the diff of two dashboard versions.
+func getDiff(originalDash, newDash *models.DashboardVersion) (interface{}, diff.Diff, error) {
+	leftBytes, err := simplejson.NewFromAny(originalDash).Encode()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	rightBytes, err := simplejson.NewFromAny(newDash).Encode()
+	if err != nil {
+		return nil, nil, err
+	}
+
+	jsonDiff, err := diff.New().Compare(leftBytes, rightBytes)
+	if err != nil {
+		return nil, nil, err
+	}
+
+	if !jsonDiff.Modified() {
+		return nil, nil, ErrNilDiff
+	}
+
+	left := make(map[string]interface{})
+	err = json.Unmarshal(leftBytes, &left)
+	return left, jsonDiff, nil
+}

pkg/components/dashdiffs/formatter_basic.go

@@ -1,4 +1,4 @@
-package formatter
+package dashdiffs
 
 import (
 	"bytes"
@@ -261,7 +261,7 @@ var (
 				line-display="{{ .LineStart }}{{ if .LineEnd }} - {{ .LineEnd }}{{ end }}"
 				switch-view="ctrl.getDiff('html')"
 			/>
-		{{ end }} 
+		{{ end }}
 
 	</div>
 
@@ -286,7 +286,7 @@ var (
 <li class="diff-change-group">
 	<span class="bullet-position-container">
 		<div class="diff-change-item diff-change-title">{{ getChange .Change }} {{ .Key }}</div>
-		
+
 		<div class="diff-change-item">
 			{{ if .Old }}
 				<div class="change list-change diff-label">{{ .Old }}</div>
@@ -312,7 +312,7 @@ var (
 	tplSummary = `{{ define "summary" -}}
 <div class="diff-group-name">
 	<i class="diff-circle diff-circle-{{ getChange .Change }} fa fa-circle-o diff-list-circle"></i>
-	
+
 	{{ if .Count }}
 		<strong>{{ .Count }}</strong>
 	{{ end }}

pkg/components/dashdiffs/formatter_json.go

@@ -1,4 +1,4 @@
-package formatter
+package dashdiffs
 
 import (
 	"bytes"