feat: support png, jpg, jpeg, gif for icon auto-detection

internal/icon/icon.go

@@ -0,0 +1,38 @@
+// Copyright 2022-2026 Salesforce, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package icon
+
+import (
+	"path/filepath"
+
+	"github.com/spf13/afero"
+)
+
+var SupportedExtensions = []string{".png", ".jpg", ".jpeg", ".gif"}
+
+func ResolveIconPath(fs afero.Fs, manifestIcon string) string {
+	if manifestIcon != "" {
+		return manifestIcon
+	}
+	for _, dir := range []string{"assets", "."} {
+		for _, ext := range SupportedExtensions {
+			candidate := filepath.Join(dir, "icon"+ext)
+			if _, err := fs.Stat(candidate); err == nil {
+				return candidate
+			}
+		}
+	}
+	return ""
+}

internal/icon/icon_test.go

@@ -0,0 +1,86 @@
+// Copyright 2022-2026 Salesforce, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package icon
+
+import (
+	"testing"
+
+	"github.com/spf13/afero"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func Test_ResolveIconPath(t *testing.T) {
+	tests := map[string]struct {
+		manifestIcon string
+		files        []string
+		expected     string
+	}{
+		"manifest icon set returns it directly": {
+			manifestIcon: "custom/my-icon.png",
+			expected:     "custom/my-icon.png",
+		},
+		"assets/icon.png found": {
+			files:    []string{"assets/icon.png"},
+			expected: "assets/icon.png",
+		},
+		"assets/icon.jpg found": {
+			files:    []string{"assets/icon.jpg"},
+			expected: "assets/icon.jpg",
+		},
+		"assets/icon.jpeg found": {
+			files:    []string{"assets/icon.jpeg"},
+			expected: "assets/icon.jpeg",
+		},
+		"assets/icon.gif found": {
+			files:    []string{"assets/icon.gif"},
+			expected: "assets/icon.gif",
+		},
+		"png wins over gif in assets": {
+			files:    []string{"assets/icon.png", "assets/icon.gif"},
+			expected: "assets/icon.png",
+		},
+		"jpg wins over gif in assets": {
+			files:    []string{"assets/icon.jpg", "assets/icon.gif"},
+			expected: "assets/icon.jpg",
+		},
+		"root icon.png found when no assets": {
+			files:    []string{"icon.png"},
+			expected: "icon.png",
+		},
+		"root icon.jpg found when no assets": {
+			files:    []string{"icon.jpg"},
+			expected: "icon.jpg",
+		},
+		"assets takes priority over root": {
+			files:    []string{"assets/icon.gif", "icon.png"},
+			expected: "assets/icon.gif",
+		},
+		"no icon files returns empty": {
+			files:    []string{},
+			expected: "",
+		},
+	}
+	for name, tc := range tests {
+		t.Run(name, func(t *testing.T) {
+			fs := afero.NewMemMapFs()
+			for _, f := range tc.files {
+				require.NoError(t, afero.WriteFile(fs, f, []byte("img"), 0o644))
+			}
+			result := ResolveIconPath(fs, tc.manifestIcon)
+			assert.Equal(t, tc.expected, result)
+		})
+	}
+}

internal/pkg/apps/install.go

@@ -17,14 +17,14 @@ package apps
 import (
 	"context"
 	"fmt"
-	"os"
 	"strings"
 	"time"
 
 	"github.com/opentracing/opentracing-go"
 	"github.com/slackapi/slack-cli/internal/api"
 	"github.com/slackapi/slack-cli/internal/config"
 	"github.com/slackapi/slack-cli/internal/experiment"
+	"github.com/slackapi/slack-cli/internal/icon"
 	"github.com/slackapi/slack-cli/internal/pkg/manifest"
 	"github.com/slackapi/slack-cli/internal/shared"
 	"github.com/slackapi/slack-cli/internal/shared/types"
@@ -218,13 +218,8 @@ func Install(ctx context.Context, clients *shared.ClientFactory, auth types.Slac
 		}
 	}
 
-	// upload icon, default to icon.png
-	var iconPath = slackManifest.Icon
-	if iconPath == "" {
-		if _, err := os.Stat("icon.png"); !os.IsNotExist(err) {
-			iconPath = "icon.png"
-		}
-	}
+	// upload icon, default to assets/icon.{png,jpg,jpeg,gif} or icon.{png,jpg,jpeg,gif}
+	iconPath := icon.ResolveIconPath(clients.Fs, slackManifest.Icon)
 	if iconPath != "" {
 		err = updateIcon(ctx, clients, iconPath, app.AppID, token, manifest.IsFunctionRuntimeSlackHosted())
 		if err != nil {
@@ -524,12 +519,7 @@ func InstallLocalApp(ctx context.Context, clients *shared.ClientFactory, orgGran
 
 	// upload icon for non-hosted apps (gated behind set-icon experiment)
 	if clients.Config.WithExperimentOn(experiment.SetIcon) {
-		var iconPath = slackManifest.Icon
-		if iconPath == "" {
-			if _, err := os.Stat("icon.png"); !os.IsNotExist(err) {
-				iconPath = "icon.png"
-			}
-		}
+		iconPath := icon.ResolveIconPath(clients.Fs, slackManifest.Icon)
 		if iconPath != "" {
 			_, iconErr := clients.API().IconSet(ctx, clients.Fs, token, app.AppID, iconPath)
 			if iconErr != nil {

internal/shared/types/slack_yaml.go

@@ -18,7 +18,9 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/slackapi/slack-cli/internal/icon"
 	"github.com/slackapi/slack-cli/internal/slackerror"
+	"github.com/spf13/afero"
 )
 
 type SlackYaml struct {
@@ -28,28 +30,24 @@ type SlackYaml struct {
 }
 
 // hasValidIconPath returns false if icon path is provided but is not valid and true otherwise
-func (sy *SlackYaml) hasValidIconPath() bool {
-	// verify icon path is valid if exists
-	var wd, err = os.Getwd()
-	if err == nil {
-		if sy.Icon == "" { // icon was not provided.  Let's check if the default one exists
-			var defaultIconPath = "assets/icon.png"
-			if _, err := os.Stat(filepath.Join(wd, defaultIconPath)); !os.IsNotExist(err) {
-				sy.Icon = defaultIconPath
-			}
-		} else {
-			if _, err := os.Stat(filepath.Join(wd, sy.Icon)); os.IsNotExist(err) {
-				return false
-			}
+func (sy *SlackYaml) hasValidIconPath(fs afero.Fs) bool {
+	wd, err := os.Getwd()
+	if err != nil {
+		return true
+	}
+	if sy.Icon == "" {
+		sy.Icon = icon.ResolveIconPath(afero.NewBasePathFs(fs, wd), "")
+	} else {
+		if _, err := fs.Stat(filepath.Join(wd, sy.Icon)); os.IsNotExist(err) {
+			return false
 		}
 	}
-
 	return true
 }
 
 // Verify checks that the app manifest meets some basic requirements
-func (sy *SlackYaml) Verify() error {
-	if !sy.hasValidIconPath() {
+func (sy *SlackYaml) Verify(fs afero.Fs) error {
+	if !sy.hasValidIconPath(fs) {
 		return slackerror.New("Please specify a valid icon path in app manifest")
 	}
 	return nil

internal/shared/types/slack_yaml_test.go

@@ -19,6 +19,7 @@ import (
 	"path/filepath"
 	"testing"
 
+	"github.com/spf13/afero"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -50,6 +51,31 @@ func Test_SlackYaml_hasValidIconPath(t *testing.T) {
 			},
 			expected: true,
 		},
+		"no icon with default assets/icon.jpg present returns true": {
+			icon: "",
+			setup: func(t *testing.T, dir string) {
+				require.NoError(t, os.MkdirAll(filepath.Join(dir, "assets"), 0o755))
+				require.NoError(t, os.WriteFile(filepath.Join(dir, "assets", "icon.jpg"), []byte("img"), 0o644))
+			},
+			expected: true,
+		},
+		"no icon with default assets/icon.gif present returns true": {
+			icon: "",
+			setup: func(t *testing.T, dir string) {
+				require.NoError(t, os.MkdirAll(filepath.Join(dir, "assets"), 0o755))
+				require.NoError(t, os.WriteFile(filepath.Join(dir, "assets", "icon.gif"), []byte("img"), 0o644))
+			},
+			expected: true,
+		},
+		"png takes priority over jpg in assets": {
+			icon: "",
+			setup: func(t *testing.T, dir string) {
+				require.NoError(t, os.MkdirAll(filepath.Join(dir, "assets"), 0o755))
+				require.NoError(t, os.WriteFile(filepath.Join(dir, "assets", "icon.png"), []byte("img"), 0o644))
+				require.NoError(t, os.WriteFile(filepath.Join(dir, "assets", "icon.jpg"), []byte("img"), 0o644))
+			},
+			expected: true,
+		},
 		"no icon and no default returns true": {
 			icon:     "",
 			setup:    func(t *testing.T, dir string) {},
@@ -67,7 +93,7 @@ func Test_SlackYaml_hasValidIconPath(t *testing.T) {
 			defer func() { require.NoError(t, os.Chdir(origDir)) }()
 
 			sy := &SlackYaml{Icon: tc.icon}
-			assert.Equal(t, tc.expected, sy.hasValidIconPath())
+			assert.Equal(t, tc.expected, sy.hasValidIconPath(afero.NewOsFs()))
 		})
 	}
 }
@@ -103,9 +129,9 @@ func Test_SlackYaml_Verify(t *testing.T) {
 
 			sy := &SlackYaml{Icon: tc.icon}
 			if tc.expectErr {
-				assert.Error(t, sy.Verify())
+				assert.Error(t, sy.Verify(afero.NewOsFs()))
 			} else {
-				assert.NoError(t, sy.Verify())
+				assert.NoError(t, sy.Verify(afero.NewOsFs()))
 			}
 		})
 	}