Add helper functions to make some code clearer

Author: code-asher

src/common/util.ts

@@ -33,6 +33,13 @@ export const normalize = (url: string, keepTrailing = false): string => {
   return url.replace(/\/\/+/g, "/").replace(/\/+$/, keepTrailing ? "/" : "")
 }
 
+/**
+ * Remove leading and trailing slashes.
+ */
+export const trimSlashes = (url: string): string => {
+  return url.replace(/^\/+|\/+$/g, "")
+}
+
 /**
  * Get options embedded in the HTML or query params.
  */
@@ -75,3 +82,17 @@ export const getOptions = <T extends Options>(): T => {
 
   return options
 }
+
+/**
+ * Wrap the value in an array if it's not already an array. If the value is
+ * undefined return an empty array.
+ */
+export const arrayify = <T>(value?: T | T[]): T[] => {
+  if (Array.isArray(value)) {
+    return value
+  }
+  if (typeof value === "undefined") {
+    return []
+  }
+  return [value]
+}

src/node/app/vscode.ts

@@ -14,7 +14,7 @@ import {
   WorkbenchOptions,
 } from "../../../lib/vscode/src/vs/server/ipc"
 import { HttpCode, HttpError } from "../../common/http"
-import { generateUuid } from "../../common/util"
+import { arrayify, generateUuid } from "../../common/util"
 import { Args } from "../cli"
 import { HttpProvider, HttpProviderOptions, HttpResponse, Route } from "../http"
 import { settings } from "../settings"
@@ -224,8 +224,7 @@ export class VscodeHttpProvider extends HttpProvider {
     }
     for (let i = 0; i < startPaths.length; ++i) {
       const startPath = startPaths[i]
-      const url =
-        startPath && (typeof startPath.url === "string" ? [startPath.url] : startPath.url || []).find((p) => !!p)
+      const url = arrayify(startPath && startPath.url).find((p) => !!p)
       if (startPath && url) {
         return {
           url,

src/node/http.ts

@@ -12,7 +12,7 @@ import { Readable } from "stream"
 import * as tls from "tls"
 import * as url from "url"
 import { HttpCode, HttpError } from "../common/http"
-import { normalize, Options, plural, split } from "../common/util"
+import { arrayify, normalize, Options, plural, split, trimSlashes } from "../common/util"
 import { SocketProxyProvider } from "./socket"
 import { getMediaMime, paths } from "./util"
 
@@ -287,7 +287,7 @@ export abstract class HttpProvider {
    * Helper to error on invalid methods (default GET).
    */
   protected ensureMethod(request: http.IncomingMessage, method?: string | string[]): void {
-    const check = Array.isArray(method) ? method : [method || "GET"]
+    const check = arrayify(method || "GET")
     if (!request.method || !check.includes(request.method)) {
       throw new HttpError(`Unsupported method ${request.method}`, HttpCode.BadRequest)
     }
@@ -559,7 +559,7 @@ export class HttpServer {
       },
       ...args,
     )
-    const endpoints = (typeof endpoint === "string" ? [endpoint] : endpoint).map((e) => e.replace(/^\/+|\/+$/g, ""))
+    const endpoints = arrayify(endpoint).map(trimSlashes)
     endpoints.forEach((endpoint) => {
       if (/\//.test(endpoint)) {
         throw new Error(`Only top-level endpoints are supported (got ${endpoint})`)