fix: add support for licenses not found on list (#1540)

Signed-off-by: Avi Deitcher <avi@deitcher.net>

internal/spdxlicense/license.go

@@ -12,9 +12,22 @@ import (
 // EX: gpl-2.0.0-only ---> GPL-2.0-only
 // See the debian link for more details on the spdx license differences
 
+const (
+	LicenseRefPrefix = "LicenseRef-" // prefix for non-standard licenses
+)
+
 //go:generate go run ./generate
 
-func ID(id string) (string, bool) {
-	value, exists := licenseIDs[strings.ToLower(id)]
-	return value, exists
+func ID(id string) (value, other string, exists bool) {
+	id = strings.TrimSpace(id)
+	// ignore blank strings or the joiner
+	if id == "" || id == "AND" {
+		return "", "", false
+	}
+	// first look for a canonical license
+	if value, exists := licenseIDs[strings.ToLower(id)]; exists {
+		return value, "", exists
+	}
+	// we did not find, so treat it as a separate license
+	return "", id, true
 }

internal/spdxlicense/license_test.go

@@ -9,52 +9,91 @@ import (
 func TestIDParse(t *testing.T) {
 	var tests = []struct {
 		shortName string
-		spdx      string
+		id        string
+		other     string
+		found     bool
 	}{
 		{
 			"GPL-1-only",
 			"GPL-1.0-only",
+			"",
+			true,
 		},
 		{
 			"GPL-2",
 			"GPL-2.0-only",
+			"",
+			true,
 		},
 		{
 			"GPL-2+",
 			"GPL-2.0-or-later",
+			"",
+			true,
 		},
 		{
 			"GPL-3.0.0-or-later",
 			"GPL-3.0-or-later",
+			"",
+			true,
 		},
 		{
 			"GPL-3-with-autoconf-exception",
 			"GPL-3.0-with-autoconf-exception",
+			"",
+			true,
 		},
 		{
 			"CC-by-nc-3-de",
 			"CC-BY-NC-3.0-DE",
+			"",
+			true,
 		},
 		// the below few cases are NOT expected, however, seem unavoidable given the current approach
 		{
 			"w3c-20150513.0.0",
 			"W3C-20150513",
+			"",
+			true,
 		},
 		{
 			"spencer-86.0.0",
 			"Spencer-86",
+			"",
+			true,
 		},
 		{
 			"unicode-dfs-2015.0.0",
 			"Unicode-DFS-2015",
+			"",
+			true,
+		},
+		{
+			"Unknown",
+			"",
+			"Unknown",
+			true,
+		},
+		{
+			"   ",
+			"",
+			"",
+			false,
+		},
+		{
+			"AND",
+			"",
+			"",
+			false,
 		},
 	}
 
 	for _, test := range tests {
 		t.Run(test.shortName, func(t *testing.T) {
-			got, exists := ID(test.shortName)
-			assert.True(t, exists)
-			assert.Equal(t, test.spdx, got)
+			value, other, exists := ID(test.shortName)
+			assert.Equal(t, test.found, exists)
+			assert.Equal(t, test.id, value)
+			assert.Equal(t, test.other, other)
 		})
 	}
 }