refactor: Drop headers support of Utils.fetchLite()

The `accept` header is important for Registry NPM, but unfortunately it has a "bug" that makes it currently useless (npm/feedback#831).

Author: david-rodrigues

src/NPM.ts

@@ -35,17 +35,15 @@ export const getPackageVersions = async (
   // This avoids loading processes via `npm view`.
   // The process is cached if it is triggered quickly, within lifetime.
   const execPromise = new Promise<string[] | null>((resolve) =>
-    fetchLite<NPMRegistryPackage>(
-      `https://registry.npmjs.org/${name}`,
-      undefined,
-      { Accept: "application/vnd.npm.install-v1+json" } // Optimal version (~50% smaller response).
-    ).then((data) => {
-      if (data?.versions) {
-        return resolve(Object.keys(data.versions))
-      }
+    fetchLite<NPMRegistryPackage>(`https://registry.npmjs.org/${name}`).then(
+      (data) => {
+        if (data?.versions) {
+          return resolve(Object.keys(data.versions))
+        }
 
-      return resolve(null)
-    })
+        return resolve(null)
+      }
+    )
   )
 
   packagesCache.set(name, new Cache(execPromise))
@@ -152,7 +150,6 @@ export const getPackagesAdvisories = async (
     const responseAdvisories = await fetchLite<PackagesAdvisories | undefined>(
       "https://registry.npmjs.org/-/npm/v1/security/advisories/bulk",
       "post",
-      undefined,
       packages
     )
 

src/Utils.test.ts

@@ -139,7 +139,6 @@ describe("utils", () => {
     const fetchSuccess = await fetchLite(
       "https://registry.npmjs.org/-/npm/v1/security/advisories/bulk",
       "post",
-      undefined,
       { "npm-outdated": ["2.0.3"] }
     )
 
@@ -150,9 +149,7 @@ describe("utils", () => {
     expect.assertions(1)
 
     const fetchSuccess = await fetchLite(
-      "https://registry.npmjs.org/node-fetch",
-      undefined,
-      { Accept: "application/vnd.npm.install-v1+json" }
+      "https://registry.npmjs.org/node-fetch"
     )
 
     expect(fetchSuccess).toBeInstanceOf(Object)

src/Utils.ts

@@ -125,7 +125,6 @@ export const cacheEnabled = (): boolean => true
 export const fetchLite = <T>(
   paramUrl: string,
   method?: "get" | "post" | undefined,
-  paramHeaders?: Record<string, string> | undefined,
   body?: object | undefined
 ): Promise<T | undefined> => {
   return new Promise<T | undefined>((resolve) => {
@@ -135,29 +134,26 @@ export const fetchLite = <T>(
     const thisReq = https.request(
       { headers, hostname, method: method ?? "get", path },
       (response: IncomingMessage) => {
-        const respondeBuffers: Buffer[] = []
+        const responseBuffers: Buffer[] = []
 
-        response.on("data", (data: Buffer) => respondeBuffers.push(data))
+        response.on("data", (data: Buffer) => responseBuffers.push(data))
         // istanbul ignore next
         response.on("error", () => resolve(undefined))
-        response.on("end", () =>
-          zlib.gunzip(Buffer.concat(respondeBuffers), (_error, contents) => {
-            resolve(JSON.parse(contents.toString()))
-          })
-        )
+        response.on("end", () => {
+          return zlib.gunzip(
+            Buffer.concat(responseBuffers),
+            (_error, contents) => {
+              resolve(JSON.parse(contents.toString()))
+            }
+          )
+        })
       }
     )
 
     thisReq.setHeader("Content-Type", "application/json")
     thisReq.setHeader("Content-Encoding", "gzip")
     thisReq.setHeader("Accept-Encoding", "gzip")
 
-    if (paramHeaders) {
-      Object.entries(headers).forEach(([headerName, headerValue]) =>
-        thisReq.setHeader(headerName, headerValue)
-      )
-    }
-
     if (body !== undefined) {
       const bodyStringify = zlib.gzipSync(JSON.stringify(body))