refactor: refactor warn function

Author: Hazlank

src/components/link.js

@@ -112,40 +112,33 @@ export default {
       })
 
     if (scopedSlot) {
-      if (process.env.NODE_ENV !== 'production' && !this.custom) {
-        !warnedCustomSlot && warn(false, 'In Vue Router 4, the v-slot API will by default wrap its content with an <a> element. Use the custom prop to remove this warning:\n<router-link v-slot="{ navigate, href }" custom></router-link>\n')
+      if (!this.custom) {
+        !warnedCustomSlot && warn('In Vue Router 4, the v-slot API will by default wrap its content with an <a> element. Use the custom prop to remove this warning:\n<router-link v-slot="{ navigate, href }" custom></router-link>\n')
         warnedCustomSlot = true
       }
       if (scopedSlot.length === 1) {
         return scopedSlot[0]
       } else if (scopedSlot.length > 1 || !scopedSlot.length) {
-        if (process.env.NODE_ENV !== 'production') {
-          warn(
-            false,
-            `<router-link> with to="${
-              this.to
-            }" is trying to use a scoped slot but it didn't provide exactly one child. Wrapping the content with a span element.`
-          )
-        }
+        warn(
+          `<router-link> with to="${
+            this.to
+          }" is trying to use a scoped slot but it didn't provide exactly one child. Wrapping the content with a span element.`
+        )
         return scopedSlot.length === 0 ? h() : h('span', {}, scopedSlot)
       }
     }
 
-    if (process.env.NODE_ENV !== 'production') {
-      if ('tag' in this.$options.propsData && !warnedTagProp) {
-        warn(
-          false,
-          `<router-link>'s tag prop is deprecated and has been removed in Vue Router 4. Use the v-slot API to remove this warning: https://next.router.vuejs.org/guide/migration/#removal-of-event-and-tag-props-in-router-link.`
-        )
-        warnedTagProp = true
-      }
-      if ('event' in this.$options.propsData && !warnedEventProp) {
-        warn(
-          false,
-          `<router-link>'s event prop is deprecated and has been removed in Vue Router 4. Use the v-slot API to remove this warning: https://next.router.vuejs.org/guide/migration/#removal-of-event-and-tag-props-in-router-link.`
-        )
-        warnedEventProp = true
-      }
+    if ('tag' in this.$options.propsData && !warnedTagProp) {
+      warn(
+        `<router-link>'s tag prop is deprecated and has been removed in Vue Router 4. Use the v-slot API to remove this warning: https://next.router.vuejs.org/guide/migration/#removal-of-event-and-tag-props-in-router-link.`
+      )
+      warnedTagProp = true
+    }
+    if ('event' in this.$options.propsData && !warnedEventProp) {
+      warn(
+        `<router-link>'s event prop is deprecated and has been removed in Vue Router 4. Use the v-slot API to remove this warning: https://next.router.vuejs.org/guide/migration/#removal-of-event-and-tag-props-in-router-link.`
+      )
+      warnedEventProp = true
     }
 
     if (this.tag === 'a') {

src/components/view.js

@@ -144,12 +144,9 @@ function resolveProps (route, config) {
     case 'boolean':
       return config ? route.params : undefined
     default:
-      if (process.env.NODE_ENV !== 'production') {
-        warn(
-          false,
-          `props in "${route.path}" is a ${typeof config}, ` +
-          `expecting an object, function or boolean.`
-        )
-      }
+      warn(
+        `props in "${route.path}" is a ${typeof config}, ` +
+        `expecting an object, function or boolean.`
+      )
   }
 }

src/create-matcher.js

@@ -58,8 +58,8 @@ export function createMatcher (
 
     if (name) {
       const record = nameMap[name]
-      if (process.env.NODE_ENV !== 'production') {
-        warn(record, `Route with name '${name}' does not exist`)
+      if (!record) {
+        warn(`Route with name '${name}' does not exist`)
       }
       if (!record) return _createRoute(null, location)
       const paramNames = record.regex.keys
@@ -108,11 +108,9 @@ export function createMatcher (
     }
 
     if (!redirect || typeof redirect !== 'object') {
-      if (process.env.NODE_ENV !== 'production') {
-        warn(
-          false, `invalid redirect option: ${JSON.stringify(redirect)}`
-        )
-      }
+      warn(
+        `invalid redirect option: ${JSON.stringify(redirect)}`
+      )
       return _createRoute(null, location)
     }
 
@@ -149,9 +147,7 @@ export function createMatcher (
         hash
       }, undefined, location)
     } else {
-      if (process.env.NODE_ENV !== 'production') {
-        warn(false, `invalid redirect option: ${JSON.stringify(redirect)}`)
-      }
+      warn(`invalid redirect option: ${JSON.stringify(redirect)}`)
       return _createRoute(null, location)
     }
   }

src/create-route-map.js

@@ -35,16 +35,14 @@ export function createRouteMap (
     }
   }
 
-  if (process.env.NODE_ENV === 'development') {
-    // warn if routes do not include leading slashes
-    const found = pathList
-    // check for missing leading slash
-      .filter(path => path && path.charAt(0) !== '*' && path.charAt(0) !== '/')
-
-    if (found.length > 0) {
-      const pathNames = found.map(path => `- ${path}`).join('\n')
-      warn(false, `Non-nested routes must include a leading slash character. Fix the following routes: \n${pathNames}`)
-    }
+  // warn if routes do not include leading slashes
+  const found = pathList
+  // check for missing leading slash
+    .filter(path => path && path.charAt(0) !== '*' && path.charAt(0) !== '/')
+
+  if (found.length > 0) {
+    const pathNames = found.map(path => `- ${path}`).join('\n')
+    warn(`Non-nested routes must include a leading slash character. Fix the following routes: \n${pathNames}`)
   }
 
   return {
@@ -71,10 +69,10 @@ function addRouteRecord (
         path || name
       )} cannot be a ` + `string id. Use an actual component instead.`
     )
-
+  }
+  // eslint-disable-next-line no-control-regex
+  if (/[^\u0000-\u007F]+/.test(path)) {
     warn(
-      // eslint-disable-next-line no-control-regex
-      !/[^\u0000-\u007F]+/.test(path),
       `Route with path "${path}" contains unencoded characters, make sure ` +
         `your path is correctly encoded before passing it to the router. Use ` +
         `encodeURI to encode static segments of your path.`
@@ -118,23 +116,20 @@ function addRouteRecord (
     // Warn if route is named, does not redirect and has a default child route.
     // If users navigate to this route by name, the default child will
     // not be rendered (GH Issue #629)
-    if (process.env.NODE_ENV !== 'production') {
-      if (
-        route.name &&
-        !route.redirect &&
-        route.children.some(child => /^\/?$/.test(child.path))
-      ) {
-        warn(
-          false,
-          `Named Route '${route.name}' has a default child route. ` +
-            `When navigating to this named route (:to="{name: '${
-              route.name
-            }'"), ` +
-            `the default child route will not be rendered. Remove the name from ` +
-            `this route and use the name of the default child route for named ` +
-            `links instead.`
-        )
-      }
+    if (
+      route.name &&
+      !route.redirect &&
+      route.children.some(child => /^\/?$/.test(child.path))
+    ) {
+      warn(
+        `Named Route '${route.name}' has a default child route. ` +
+          `When navigating to this named route (:to="{name: '${
+            route.name
+          }'"), ` +
+          `the default child route will not be rendered. Remove the name from ` +
+          `this route and use the name of the default child route for named ` +
+          `links instead.`
+      )
     }
     route.children.forEach(child => {
       const childMatchAs = matchAs
@@ -153,9 +148,8 @@ function addRouteRecord (
     const aliases = Array.isArray(route.alias) ? route.alias : [route.alias]
     for (let i = 0; i < aliases.length; ++i) {
       const alias = aliases[i]
-      if (process.env.NODE_ENV !== 'production' && alias === path) {
+      if (alias === path) {
         warn(
-          false,
           `Found an alias with the same value as the path: "${path}". You have to remove that alias. It will be ignored in development.`
         )
         // skip in dev to make it work
@@ -180,9 +174,8 @@ function addRouteRecord (
   if (name) {
     if (!nameMap[name]) {
       nameMap[name] = record
-    } else if (process.env.NODE_ENV !== 'production' && !matchAs) {
+    } else if (!matchAs) {
       warn(
-        false,
         `Duplicate named routes definition: ` +
           `{ name: "${name}", path: "${record.path}" }`
       )
@@ -195,16 +188,15 @@ function compileRouteRegex (
   pathToRegexpOptions: PathToRegexpOptions
 ): RouteRegExp {
   const regex = Regexp(path, [], pathToRegexpOptions)
-  if (process.env.NODE_ENV !== 'production') {
-    const keys: any = Object.create(null)
-    regex.keys.forEach(key => {
+  const keys: any = Object.create(null)
+  regex.keys.forEach(key => {
+    if (keys[key.name]) {
       warn(
-        !keys[key.name],
         `Duplicate param keys in route with path: "${path}"`
       )
-      keys[key.name] = true
-    })
-  }
+    }
+    keys[key.name] = true
+  })
   return regex
 }
 

src/history/base.js

@@ -146,7 +146,7 @@ export class History {
             cb(err)
           })
         } else {
-          warn(false, 'uncaught error during route navigation:')
+          warn('uncaught error during route navigation:')
           console.error(err)
         }
       }

src/index.js

@@ -39,6 +39,10 @@ export default class VueRouter {
   afterHooks: Array<?AfterNavigationHook>
 
   constructor (options: RouterOptions = {}) {
+    if (!(this instanceof VueRouter)) {
+      warn('Router must be called with the new operator.')
+    }
+
     this.app = null
     this.apps = []
     this.options = options
@@ -257,9 +261,7 @@ export default class VueRouter {
   }
 
   addRoutes (routes: Array<RouteConfig>) {
-    if (process.env.NODE_ENV !== 'production') {
-      warn(false, 'router.addRoutes() is deprecated and has been removed in Vue Router 4. Use router.addRoute() instead.')
-    }
+    warn('router.addRoutes() is deprecated and has been removed in Vue Router 4. Use router.addRoute() instead.')
     this.matcher.addRoutes(routes)
     if (this.history.current !== START) {
       this.history.transitionTo(this.history.getCurrentLocation())

src/util/location.js

@@ -38,7 +38,7 @@ export function normalizeLocation (
       const rawPath = current.matched[current.matched.length - 1].path
       next.path = fillParams(rawPath, params, `path ${current.path}`)
     } else if (process.env.NODE_ENV !== 'production') {
-      warn(false, `relative params navigation requires a current route.`)
+      warn(`relative params navigation requires a current route.`)
     }
     return next
   }

src/util/params.js

@@ -25,9 +25,9 @@ export function fillParams (
 
     return filler(params, { pretty: true })
   } catch (e) {
-    if (process.env.NODE_ENV !== 'production') {
+    if (!typeof params.pathMatch === 'string') {
       // Fix #3072 no warn if `pathMatch` is string
-      warn(typeof params.pathMatch === 'string', `missing param for ${routeMsg}: ${e.message}`)
+      warn(`missing param for ${routeMsg}: ${e.message}`)
     }
     return ''
   } finally {

src/util/query.js

@@ -18,9 +18,7 @@ export function decode (str: string) {
   try {
     return decodeURIComponent(str)
   } catch (err) {
-    if (process.env.NODE_ENV !== 'production') {
-      warn(false, `Error decoding "${str}". Leaving it intact.`)
-    }
+    warn(`Error decoding "${str}". Leaving it intact.`)
   }
   return str
 }
@@ -35,7 +33,7 @@ export function resolveQuery (
   try {
     parsedQuery = parse(query || '')
   } catch (e) {
-    process.env.NODE_ENV !== 'production' && warn(false, e.message)
+    warn(e.message)
     parsedQuery = {}
   }
   for (const key in extraQuery) {

src/util/resolve-components.js

@@ -37,7 +37,7 @@ export function resolveAsyncComponents (matched: Array<RouteRecord>): Function {
 
         const reject = once(reason => {
           const msg = `Failed to resolve async component ${key}: ${reason}`
-          process.env.NODE_ENV !== 'production' && warn(false, msg)
+          warn(msg)
           if (!error) {
             error = isError(reason)
               ? reason

src/util/warn.js

@@ -6,8 +6,8 @@ export function assert (condition: any, message: string) {
   }
 }
 
-export function warn (condition: any, message: string) {
-  if (process.env.NODE_ENV !== 'production' && !condition) {
+export function warn (message: string) {
+  if (process.env.NODE_ENV !== 'production') {
     typeof console !== 'undefined' && console.warn(`[vue-router] ${message}`)
   }
 }