diff --git a/pkg/commands/edit/add/flagsandargs.go b/pkg/commands/edit/add/flagsandargs.go
index b915cbf51..a842ed817 100644
--- a/pkg/commands/edit/add/flagsandargs.go
+++ b/pkg/commands/edit/add/flagsandargs.go
@@ -54,12 +54,28 @@ func (a *flagsAndArgs) Validate(args []string) error {
 	return nil
 }
 
+// ExpandFileSource normalizes a string list, possibly
+// containing globs, into a validated, globless list.
+// For example, this list:
+//     some/path
+//     some/dir/a*
+//     bfile=some/dir/b*
+// becomes:
+//     some/path
+//     some/dir/airplane
+//     some/dir/ant
+//     some/dir/apple
+//     bfile=some/dir/banana
+// i.e. everything is converted to a key=value pair,
+// where the value is always a relative file path,
+// and the key, if missing, is the same as the value.
+// In the case where the key is explicitly declared,
+// the globbing, if present, must have exactly one match.
 func (a *flagsAndArgs) ExpandFileSource(fSys fs.FileSystem) error {
 	var results []string
-	var key string
 	for _, pattern := range a.FileSources {
 		var patterns []string
-		key = ""
+		key := ""
 		// check if the pattern is in `--from-file=[key=]source` format
 		// and if so split it to send only the file-pattern to glob function
 		s := strings.Split(pattern, "=")
@@ -77,8 +93,8 @@ func (a *flagsAndArgs) ExpandFileSource(fSys fs.FileSystem) error {
 		// and extend it with the `key=` prefix
 		if key != "" {
 			if len(result) != 1 {
-				msg := fmt.Sprintf("%s pattern should not catch more than one file", pattern)
-				return fmt.Errorf(msg)
+				return fmt.Errorf(
+					"'pattern '%s' catches files %v, should catch only one.", pattern, result)
 			}
 			fileSource := fmt.Sprintf("%s=%s", key, result[0])
 			results = append(results, fileSource)
diff --git a/pkg/commands/edit/add/flagsandargs_test.go b/pkg/commands/edit/add/flagsandargs_test.go
index 5839f5a18..797a4639e 100644
--- a/pkg/commands/edit/add/flagsandargs_test.go
+++ b/pkg/commands/edit/add/flagsandargs_test.go
@@ -89,7 +89,7 @@ func TestExpandFileSource(t *testing.T) {
 	fakeFS := fs.MakeFakeFS()
 	fakeFS.Create("dir/fa1")
 	fakeFS.Create("dir/fa2")
-	fakeFS.Create("dir/reademe")
+	fakeFS.Create("dir/readme")
 	fa := flagsAndArgs{
 		FileSources: []string{"dir/fa*"},
 	}
@@ -105,14 +105,18 @@ func TestExpandFileSource(t *testing.T) {
 
 func TestExpandFileSourceWithKey(t *testing.T) {
 	fakeFS := fs.MakeFakeFS()
-	fakeFS.Create("dir/fa1")
-	fakeFS.Create("dir/reademe")
+	fakeFS.Create("dir/faaaaaaaaaabbbbbbbbbccccccccccccccccc")
+	fakeFS.Create("dir/foobar")
+	fakeFS.Create("dir/simplebar")
+	fakeFS.Create("dir/readme")
 	fa := flagsAndArgs{
-		FileSources: []string{"foo-key=dir/fa*"},
+		FileSources: []string{"foo-key=dir/fa*", "bar-key=dir/foobar", "dir/simplebar"},
 	}
 	fa.ExpandFileSource(fakeFS)
 	expected := []string{
-		"foo-key=dir/fa1",
+		"foo-key=dir/faaaaaaaaaabbbbbbbbbccccccccccccccccc",
+		"bar-key=dir/foobar",
+		"dir/simplebar",
 	}
 	if !reflect.DeepEqual(fa.FileSources, expected) {
 		t.Fatalf("FileSources is not correctly expanded: %v", fa.FileSources)
@@ -123,7 +127,7 @@ func TestExpandFileSourceWithKeyAndError(t *testing.T) {
 	fakeFS := fs.MakeFakeFS()
 	fakeFS.Create("dir/fa1")
 	fakeFS.Create("dir/fa2")
-	fakeFS.Create("dir/reademe")
+	fakeFS.Create("dir/readme")
 	fa := flagsAndArgs{
 		FileSources: []string{"foo-key=dir/fa*"},
 	}