Explicitely check for + and - prefixes

Author: jseminck

lib/rules/no-unused-prop-types.js

@@ -273,8 +273,11 @@ module.exports = {
      */
     function getKeyValue(node) {
       if (node.type === 'ObjectTypeProperty') {
-        const tokens = context.getFirstTokens(node, {count: 1, filter: tokenNode => ['Identifier', 'String'].indexOf(tokenNode.type) >= 0});
-        return stripQuotes(tokens[0].value);
+        const tokens = context.getFirstTokens(node, 2);
+        return (tokens[0].value === '+' || tokens[0].value === '-'
+          ? tokens[1].value
+          : stripQuotes(tokens[0].value)
+        );
       }
       const key = node.key || node.argument;
       return key.type === 'Identifier' ? key.name : key.value;

lib/rules/prop-types.js

@@ -343,8 +343,11 @@ module.exports = {
      */
     function getKeyValue(node) {
       if (node.type === 'ObjectTypeProperty') {
-        const tokens = context.getFirstTokens(node, {count: 1, filter: tokenNode => ['Identifier', 'String'].indexOf(tokenNode.type) >= 0});
-        return stripQuotes(tokens[0].value);
+        const tokens = context.getFirstTokens(node, 2);
+        return (tokens[0].value === '+' || tokens[0].value === '-'
+          ? tokens[1].value
+          : stripQuotes(tokens[0].value)
+        );
       }
       const key = node.key || node.argument;
       return key.type === 'Identifier' ? key.name : key.value;