* first action! (#1)

node_modules/validate-npm-package-license/index.js

@@ -0,0 +1,86 @@
+var parse = require('spdx-expression-parse');
+var correct = require('spdx-correct');
+
+var genericWarning = (
+  'license should be ' +
+  'a valid SPDX license expression (without "LicenseRef"), ' +
+  '"UNLICENSED", or ' +
+  '"SEE LICENSE IN <filename>"'
+);
+
+var fileReferenceRE = /^SEE LICEN[CS]E IN (.+)$/;
+
+function startsWith(prefix, string) {
+  return string.slice(0, prefix.length) === prefix;
+}
+
+function usesLicenseRef(ast) {
+  if (ast.hasOwnProperty('license')) {
+    var license = ast.license;
+    return (
+      startsWith('LicenseRef', license) ||
+      startsWith('DocumentRef', license)
+    );
+  } else {
+    return (
+      usesLicenseRef(ast.left) ||
+      usesLicenseRef(ast.right)
+    );
+  }
+}
+
+module.exports = function(argument) {
+  var ast;
+
+  try {
+    ast = parse(argument);
+  } catch (e) {
+    var match
+    if (
+      argument === 'UNLICENSED' ||
+      argument === 'UNLICENCED'
+    ) {
+      return {
+        validForOldPackages: true,
+        validForNewPackages: true,
+        unlicensed: true
+      };
+    } else if (match = fileReferenceRE.exec(argument)) {
+      return {
+        validForOldPackages: true,
+        validForNewPackages: true,
+        inFile: match[1]
+      };
+    } else {
+      var result = {
+        validForOldPackages: false,
+        validForNewPackages: false,
+        warnings: [genericWarning]
+      };
+      if (argument.trim().length !== 0) {
+        var corrected = correct(argument);
+        if (corrected) {
+          result.warnings.push(
+            'license is similar to the valid expression "' + corrected + '"'
+          );
+        }
+      }
+      return result;
+    }
+  }
+
+  if (usesLicenseRef(ast)) {
+    return {
+      validForNewPackages: false,
+      validForOldPackages: false,
+      spdx: true,
+      warnings: [genericWarning]
+    };
+  } else {
+    return {
+      validForNewPackages: true,
+      validForOldPackages: true,
+      spdx: true
+    };
+  }
+};