Fix case sensitivity in package name check (resolves #869)

Author: webpro

packages/knip/fixtures/dependencies/my-module.ts

@@ -1,4 +1,7 @@
 import has from 'has';
+import JSONStream from 'JSONStream';
+
+JSONStream;
 
 async function main() {
   return [require('ansi-regex'), import('ansi-regex')];

packages/knip/fixtures/dependencies/package.json

@@ -9,7 +9,8 @@
     "@sindresorhus/is": "*",
     "fs-extra": "*",
     "has": "*",
-    "stream": "*"
+    "stream": "*",
+    "JSONStream": "*"
   },
   "peerDependencies": {
     "ansi-regex": "*",

packages/knip/src/util/modules.ts

@@ -19,7 +19,7 @@ export const getPackageNameFromFilePath = (value: string) => {
 export const getPackageNameFromSpecifier = (specifier: string) =>
   isInNodeModules(specifier) ? getPackageNameFromFilePath(specifier) : getPackageNameFromModuleSpecifier(specifier);
 
-export const isStartsLikePackageName = (specifier: string) => /^(@[a-z0-9._]|[a-z0-9])/.test(specifier);
+export const isStartsLikePackageName = (specifier: string) => /^(@[a-z0-9._]|[a-z0-9])/i.test(specifier);
 
 export const stripVersionFromSpecifier = (specifier: string) => specifier.replace(/(\S+)@.*/, '$1');