feat: check screenshot image type

pkg/analysis/passes/screenshots/screenshots.go

@@ -3,32 +3,42 @@ package screenshots
 import (
 	"encoding/json"
 	"fmt"
+	"net/http"
+	"os"
+	"path/filepath"
 	"strings"
 
 	"github.com/grafana/plugin-validator/pkg/analysis"
+	"github.com/grafana/plugin-validator/pkg/analysis/passes/archive"
 	"github.com/grafana/plugin-validator/pkg/analysis/passes/metadata"
 )
 
 var (
-	screenshots = &analysis.Rule{Name: "screenshots", Severity: analysis.Warning}
+	screenshots     = &analysis.Rule{Name: "screenshots", Severity: analysis.Warning}
+	screenshotsType = &analysis.Rule{Name: "screenshots-image-type", Severity: analysis.Error}
 )
 
 var Analyzer = &analysis.Analyzer{
 	Name:     "screenshots",
-	Run:      checkScreenshotsExist,
-	Requires: []*analysis.Analyzer{metadata.Analyzer},
-	Rules:    []*analysis.Rule{screenshots},
+	Run:      checkScreenshots,
+	Requires: []*analysis.Analyzer{metadata.Analyzer, archive.Analyzer},
+	Rules:    []*analysis.Rule{screenshots, screenshotsType},
 	ReadmeInfo: analysis.ReadmeInfo{
 		Name:        "Screenshots",
 		Description: "Screenshots are specified in `plugin.json` that will be used in the Grafana plugin catalog.",
 	},
 }
+var acceptedImageTypes = []string{"image/jpeg", "image/png", "image/svg+xml", "image/gif"}
 
-func checkScreenshotsExist(pass *analysis.Pass) (interface{}, error) {
+func checkScreenshots(pass *analysis.Pass) (interface{}, error) {
 	metadataBody, ok := pass.ResultOf[metadata.Analyzer].([]byte)
 	if !ok {
 		return nil, nil
 	}
+	archiveDir, ok := pass.ResultOf[archive.Analyzer].(string)
+	if !ok {
+		return nil, nil
+	}
 
 	var data metadata.Metadata
 	if err := json.Unmarshal(metadataBody, &data); err != nil {
@@ -39,24 +49,59 @@ func checkScreenshotsExist(pass *analysis.Pass) (interface{}, error) {
 		explanation := "Screenshots are displayed in the Plugin catalog. Please add at least one screenshot to your plugin.json."
 		pass.ReportResult(pass.AnalyzerName, screenshots, "plugin.json: should include screenshots for the Plugin catalog", explanation)
 		return data.Info.Screenshots, nil
-	} else {
-		reportCount := 0
-		for _, screenshot := range data.Info.Screenshots {
-			if strings.TrimSpace(screenshot.Path) == "" {
-				reportCount++
-				pass.ReportResult(pass.AnalyzerName, screenshots, fmt.Sprintf("plugin.json: invalid empty screenshot path: %q", screenshot.Name), "The screenshot path must not be empty.")
-			}
-		}
+	}
 
-		if reportCount > 0 {
-			return nil, nil
+	reportCount := 0
+	for _, screenshot := range data.Info.Screenshots {
+		if strings.TrimSpace(screenshot.Path) == "" {
+			reportCount++
+			pass.ReportResult(pass.AnalyzerName, screenshots, fmt.Sprintf("plugin.json: invalid empty screenshot path: %q", screenshot.Name), "The screenshot path must not be empty.")
+		} else if !validImageType(filepath.Join(archiveDir, screenshot.Path)) {
+			reportCount++
+			pass.ReportResult(pass.AnalyzerName, screenshotsType, fmt.Sprintf("invalid screenshot image type: %q. Accepted image types: %q", screenshot.Path, acceptedImageTypes), "The screenshot image type invalid.")
 		}
+	}
 
-		if screenshots.ReportAll {
-			screenshots.Severity = analysis.OK
-			pass.ReportResult(pass.AnalyzerName, screenshots, "plugin.json: includes screenshots for the Plugin catalog", "")
-		}
+	if reportCount > 0 {
+		return nil, nil
+	}
+
+	if screenshots.ReportAll {
+		screenshots.Severity = analysis.OK
+		pass.ReportResult(pass.AnalyzerName, screenshots, "plugin.json: includes screenshots for the Plugin catalog", "")
+	}
+
+	if screenshotsType.ReportAll {
+		screenshotsType.Severity = analysis.OK
+		pass.ReportResult(pass.AnalyzerName, screenshotsType, "screenshots are valid image type", "")
 	}
 
 	return data.Info.Screenshots, nil
 }
+
+func validImageType(imgPath string) bool {
+	file, err := os.Open(imgPath)
+	if err != nil {
+		fmt.Printf("cannot open file: %v\n", err)
+		return false
+	}
+	defer file.Close()
+
+	// 512 is enough for getting the content type
+	// https://pkg.go.dev/net/http#DetectContentType
+	buffer := make([]byte, 512)
+	if _, err := file.Read(buffer); err != nil {
+		fmt.Printf("cannot read file: %v\n", err)
+		return false
+	}
+
+	mimeType := http.DetectContentType(buffer)
+
+	for _, accepted := range acceptedImageTypes {
+		if accepted == mimeType {
+			return true
+		}
+	}
+
+	return false
+}

pkg/analysis/passes/screenshots/screenshots_test.go

@@ -5,6 +5,7 @@ import (
 	"testing"
 
 	"github.com/grafana/plugin-validator/pkg/analysis"
+	"github.com/grafana/plugin-validator/pkg/analysis/passes/archive"
 	"github.com/grafana/plugin-validator/pkg/analysis/passes/metadata"
 	"github.com/grafana/plugin-validator/pkg/testpassinterceptor"
 	"github.com/stretchr/testify/require"
@@ -13,20 +14,21 @@ import (
 func TestValidScreenshots(t *testing.T) {
 	var interceptor testpassinterceptor.TestPassInterceptor
 	const pluginJsonContent = `{
-    "name": "my plugin name",
-    "info": {
-      "screenshots": [
-        {
-          "path": "img/screenshot1.png",
-          "name": "screenshot1"
-        }
-      ]
-    }
-  }`
+		"name": "my plugin name",
+		"info": {
+		"screenshots": [
+			{
+			"path": "testdata/valid.png",
+			"name": "screenshot1"
+			}
+		]
+		}
+	}`
 	pass := &analysis.Pass{
 		RootDir: filepath.Join("./"),
 		ResultOf: map[*analysis.Analyzer]interface{}{
 			metadata.Analyzer: []byte(pluginJsonContent),
+			archive.Analyzer:  filepath.Join("."),
 		},
 		Report: interceptor.ReportInterceptor(),
 	}
@@ -39,15 +41,16 @@ func TestValidScreenshots(t *testing.T) {
 func TestNoScreenshots(t *testing.T) {
 	var interceptor testpassinterceptor.TestPassInterceptor
 	const pluginJsonContent = `{
-    "name": "my plugin name",
-    "info": {
-      "screenshots": []
-    }
-  }`
+		"name": "my plugin name",
+		"info": {
+		"screenshots": []
+		}
+	}`
 	pass := &analysis.Pass{
 		RootDir: filepath.Join("./"),
 		ResultOf: map[*analysis.Analyzer]interface{}{
 			metadata.Analyzer: []byte(pluginJsonContent),
+			archive.Analyzer:  filepath.Join("."),
 		},
 		Report: interceptor.ReportInterceptor(),
 	}
@@ -62,18 +65,19 @@ func TestNoScreenshots(t *testing.T) {
 func TestInvalidScreenshotPath(t *testing.T) {
 	var interceptor testpassinterceptor.TestPassInterceptor
 	const pluginJsonContent = `{
-    "name": "my plugin name",
-    "info": {
-      "screenshots": [{
-        "path": "",
-        "name": "screenshot1"
-      }]
-    }
-  }`
+		"name": "my plugin name",
+		"info": {
+		"screenshots": [{
+			"path": "",
+			"name": "screenshot1"
+		}]
+		}
+	}`
 	pass := &analysis.Pass{
 		RootDir: filepath.Join("./"),
 		ResultOf: map[*analysis.Analyzer]interface{}{
 			metadata.Analyzer: []byte(pluginJsonContent),
+			archive.Analyzer:  filepath.Join("."),
 		},
 		Report: interceptor.ReportInterceptor(),
 	}
@@ -83,3 +87,82 @@ func TestInvalidScreenshotPath(t *testing.T) {
 	require.Len(t, interceptor.Diagnostics, 1)
 	require.Equal(t, interceptor.Diagnostics[0].Title, "plugin.json: invalid empty screenshot path: \"screenshot1\"")
 }
+
+func TestInvalidScreenshotImageType(t *testing.T) {
+	var interceptor testpassinterceptor.TestPassInterceptor
+	const pluginJsonContent = `{
+		"name": "my plugin name",
+		"info": {
+		"screenshots": [{
+			"name": "enhance your existing systems",
+			"path": "testdata/invalid.avif"
+		}]
+		}
+	}`
+	pass := &analysis.Pass{
+		RootDir: filepath.Join("./"),
+		ResultOf: map[*analysis.Analyzer]interface{}{
+			metadata.Analyzer: []byte(pluginJsonContent),
+			archive.Analyzer:  filepath.Join("."),
+		},
+		Report: interceptor.ReportInterceptor(),
+	}
+
+	_, err := Analyzer.Run(pass)
+	require.NoError(t, err)
+	require.Len(t, interceptor.Diagnostics, 1)
+	require.Equal(t, `invalid screenshot image type: "testdata/invalid.avif". Accepted image types: ["image/jpeg" "image/png" "image/svg+xml" "image/gif"]`, interceptor.Diagnostics[0].Title)
+}
+
+func TestTextfileScreenshotImage(t *testing.T) {
+	var interceptor testpassinterceptor.TestPassInterceptor
+	const pluginJsonContent = `{
+		"name": "my plugin name",
+		"info": {
+		"screenshots": [
+		{
+			"name": "test",
+			"path": "testdata/textfile.png"
+		}]
+		}
+	}`
+	pass := &analysis.Pass{
+		RootDir: filepath.Join("./"),
+		ResultOf: map[*analysis.Analyzer]interface{}{
+			metadata.Analyzer: []byte(pluginJsonContent),
+			archive.Analyzer:  filepath.Join("."),
+		},
+		Report: interceptor.ReportInterceptor(),
+	}
+
+	_, err := Analyzer.Run(pass)
+	require.NoError(t, err)
+	require.Len(t, interceptor.Diagnostics, 1)
+	require.Equal(t, `invalid screenshot image type: "testdata/textfile.png". Accepted image types: ["image/jpeg" "image/png" "image/svg+xml" "image/gif"]`, interceptor.Diagnostics[0].Title)
+}
+
+func TestJpgScreenshotImage(t *testing.T) {
+	var interceptor testpassinterceptor.TestPassInterceptor
+	const pluginJsonContent = `{
+		"name": "my plugin name",
+		"info": {
+		"screenshots": [
+		{
+			"name": "test",
+			"path": "testdata/valid.jpg"
+		}]
+		}
+	}`
+	pass := &analysis.Pass{
+		RootDir: filepath.Join("./"),
+		ResultOf: map[*analysis.Analyzer]interface{}{
+			metadata.Analyzer: []byte(pluginJsonContent),
+			archive.Analyzer:  filepath.Join("."),
+		},
+		Report: interceptor.ReportInterceptor(),
+	}
+
+	_, err := Analyzer.Run(pass)
+	require.NoError(t, err)
+	require.Len(t, interceptor.Diagnostics, 0)
+}