add support for UNLICENSE file matching (#40)

* add support for UNLICENSE file matching

* test

* Update find.go

* gofmt

* fix unit test

Co-authored-by: Yuan (Bob) Gong <[email protected]>
Co-authored-by: Yuan Gong <[email protected]>

Author: MarlonGamez

licenses/find.go

@@ -24,7 +24,7 @@ import (
 )
 
 var (
-	licenseRegexp = regexp.MustCompile(`^(?i)(LICEN(S|C)E|COPYING|README|NOTICE).*$`)
+	licenseRegexp = regexp.MustCompile(`^(?i)((UN)?LICEN(S|C)E|COPYING|README|NOTICE).*$`)
 )
 
 // Find returns the file path of the license for this package.

licenses/find_test.go

@@ -37,6 +37,7 @@ func TestFind(t *testing.T) {
 			"testdata/readme/README.md":                          "foo",
 			"testdata/lowercase/license":                         "foo",
 			"testdata/license-apache-2.0/LICENSE-APACHE-2.0.txt": "foo",
+			"testdata/unlicense/UNLICENSE":                       "unlicense",
 		},
 		licenseTypes: map[string]Type{
 			"testdata/LICENSE":                                   Notice,
@@ -47,6 +48,7 @@ func TestFind(t *testing.T) {
 			"testdata/readme/README.md":                          Notice,
 			"testdata/lowercase/license":                         Notice,
 			"testdata/license-apache-2.0/LICENSE-APACHE-2.0.txt": Notice,
+			"testdata/unlicense/UNLICENSE":                       Unencumbered,
 		},
 	}
 
@@ -108,6 +110,11 @@ func TestFind(t *testing.T) {
 			rootDir: "testdata/proprietary-license",
 			wantErr: regexp.MustCompile(`cannot find a known open source license for.*testdata/proprietary-license.*whose name matches regexp.*and locates up until.*testdata/proprietary-license`),
 		},
+		{
+			desc:            "UNLICENSE",
+			dir:             "testdata/unlicense",
+			wantLicensePath: filepath.Join(wd, "testdata/unlicense/UNLICENSE"),
+		},
 	} {
 		t.Run(test.desc, func(t *testing.T) {
 			if test.rootDir == "" {

licenses/testdata/unlicense/UNLICENSE

@@ -0,0 +1,24 @@
+This is free and unencumbered software released into the public domain.
+
+Anyone is free to copy, modify, publish, use, compile, sell, or
+distribute this software, either in source code form or as a compiled
+binary, for any purpose, commercial or non-commercial, and by any
+means.
+
+In jurisdictions that recognize copyright laws, the author or authors
+of this software dedicate any and all copyright interest in the
+software to the public domain. We make this dedication for the benefit
+of the public at large and to the detriment of our heirs and
+successors. We intend this dedication to be an overt act of
+relinquishment in perpetuity of all present and future rights to this
+software under copyright law.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
+IN NO EVENT SHALL THE AUTHORS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+OTHER DEALINGS IN THE SOFTWARE.
+
+For more information, please refer to <http://unlicense.org/>