Customizable copyright string check

README.md

@@ -20,6 +20,7 @@ addlicense requires go 1.16 or later.
     -f custom license file (no default)
     -l license type: apache, bsd, mit, mpl (defaults to "apache")
     -y year (defaults to current year)
+    -x custom license check, can be used with custom license to properly check presence of header (defaults to "(c)")
     -check check only mode: verify presence of license headers and exit with non-zero code if missing
     -ignore file patterns to ignore, for example: -ignore **/*.go -ignore vendor/**
 

main.go

@@ -57,6 +57,7 @@ var (
 	license   = flag.String("l", "apache", "license type: apache, bsd, mit, mpl")
 	licensef  = flag.String("f", "", "license file")
 	year      = flag.String("y", fmt.Sprint(time.Now().Year()), "copyright year(s)")
+	copyright = flag.String("x", "(c)", "custom copyright string used to determine license header presence")
 	verbose   = flag.Bool("v", false, "verbose mode: print the name of the files that are modified")
 	checkonly = flag.Bool("check", false, "check only mode: verify presence of license headers and exit with non-zero code if missing")
 )
@@ -371,5 +372,6 @@ func hasLicense(b []byte) bool {
 	}
 	return bytes.Contains(bytes.ToLower(b[:n]), []byte("copyright")) ||
 		bytes.Contains(bytes.ToLower(b[:n]), []byte("mozilla public")) ||
-		bytes.Contains(bytes.ToLower(b[:n]), []byte("spdx-license-identifier"))
+		bytes.Contains(bytes.ToLower(b[:n]), []byte("spdx-license-identifier")) ||
+		bytes.Contains(bytes.ToLower(b[:n]), []byte(*copyright))
 }

main_test.go

@@ -89,6 +89,31 @@ func TestMultiyear(t *testing.T) {
 	run(t, "diff", samplefile, sampleLicensed)
 }
 
+func TestCustomCopyright(t *testing.T) {
+	if os.Getenv("RUNME") != "" {
+		main()
+		return
+	}
+
+	tmp := tempDir(t)
+	t.Logf("tmp dir: %s", tmp)
+	samplefile := filepath.Join(tmp, "file.c")
+	const sampleLicensed = "testdata/custom_copyright_file.c"
+	const customLicense = "testdata/custom_copyright.tpl"
+
+	run(t, "cp", "testdata/initial/file.c", samplefile)
+	cmd := exec.Command(os.Args[0],
+		"-test.run=TestCustomCopyright",
+		"-f", customLicense, "-c", "Google LLC", "-y", "2022",
+		"-x", "©", samplefile,
+	)
+	cmd.Env = []string{"RUNME=1"}
+	if out, err := cmd.CombinedOutput(); err != nil {
+		t.Fatalf("%v\n%s", err, out)
+	}
+	run(t, "diff", samplefile, sampleLicensed)
+}
+
 func TestWriteErrors(t *testing.T) {
 	if os.Getenv("RUNME") != "" {
 		main()
@@ -248,6 +273,7 @@ func TestAddLicense(t *testing.T) {
 		// ensure files with existing license or generated files are
 		// skipped. No need to test all permutations of these, since
 		// there are specific tests below.
+		{"// (c) 2022 Acme\ncontent", "// (c) 2022 Acme\ncontent", false},
 		{"// Copyright 2000 Acme\ncontent", "// Copyright 2000 Acme\ncontent", false},
 		{"// Code generated by go generate; DO NOT EDIT.\ncontent", "// Code generated by go generate; DO NOT EDIT.\ncontent", false},
 	}
@@ -395,6 +421,7 @@ func TestHasLicense(t *testing.T) {
 
 		{"Copyright 2000", true},
 		{"CoPyRiGhT 2000", true},
+		{"(c) 2022", true},
 		{"Subject to the terms of the Mozilla Public License", true},
 		{"SPDX-License-Identifier: MIT", true},
 		{"spdx-license-identifier: MIT", true},

testdata/custom_copyright.tpl

@@ -0,0 +1,3 @@
+© {{.Year}} {{.Holder}}
+
+Custom License Template

testdata/custom_copyright_file.c

@@ -0,0 +1,12 @@
+/*
+ * © 2022 Google LLC
+ *
+ * Custom License Template
+ */
+
+#include <stdio.h>
+
+int main() {
+	printf("Hello world\n");
+	return 0;
+}