Add no-implicit-coercion ESLint rule (#1405)

.eslintrc.js

@@ -29,6 +29,7 @@ module.exports = {
     'func-name-matching': [2, { considerPropertyDescriptor: true }],
     'multiline-comment-style': [2, 'separate-lines'],
     'no-else-return': [2, { allowElseIf: false }],
+    'no-implicit-coercion': 2,
     'no-var': 2,
 
     // This version of eslint-plugin-unicorn requires Node 10

src/utils/init/config-manual.js

@@ -69,8 +69,7 @@ async function configManual(ctx, site, repo) {
         name: 'repoPath',
         message: 'The SSH URL of the remote git repo:',
         default: repo.repo_path,
-        validate: (url) =>
-          !!url.match(/(ssh:\/\/|[a-zA-Z]*@|[a-zA-Z.].*:(?!\/\/))/) || 'The URL provided does not use the SSH protocol',
+        validate: (url) => SSH_URL_REGEXP.test(url) || 'The URL provided does not use the SSH protocol',
       },
     ])
     repo.repo_path = repoPath
@@ -98,3 +97,5 @@ async function configManual(ctx, site, repo) {
     ctx.exit()
   }
 }
+
+const SSH_URL_REGEXP = /(ssh:\/\/|[a-zA-Z]*@|[a-zA-Z.].*:(?!\/\/))/

src/utils/serve-functions.js

@@ -99,6 +99,12 @@ const clearCache = (action) => (path) => {
   console.log(`${NETLIFYDEVLOG} ${path} ${action}, successfully reloaded!`)
 }
 
+const shouldBase64Encode = function (contentType) {
+  return Boolean(contentType) && BASE_64_MIME_REGEXP.test(contentType)
+}
+
+const BASE_64_MIME_REGEXP = /image|audio|video|application\/pdf|application\/zip|applicaton\/octet-stream/i
+
 function createHandler(dir) {
   const functions = getFunctions(dir)
 
@@ -125,10 +131,7 @@ function createHandler(dir) {
     }
     const { functionPath } = functions[func]
 
-    const isBase64Encoded = !!(request.headers['content-type'] || '')
-      .toLowerCase()
-      .match(/image|audio|video|application\/pdf|application\/zip|applicaton\/octet-stream/)
-
+    const isBase64Encoded = shouldBase64Encode(request.headers['content-type'])
     const body = request.get('content-length') ? request.body.toString(isBase64Encoded ? 'base64' : 'utf8') : undefined
 
     let remoteAddress = request.get('x-forwarded-for') || request.connection.remoteAddress || ''