Fetch versions directly from npm registry url

src/NpmRegistry.res

@@ -0,0 +1,25 @@
+type response
+
+@send external toJson: response => promise<Js.Json.t> = "json"
+@val external fetch: string => promise<response> = "fetch"
+
+let getPackageVersions = async (packageName, range) => {
+  let result = await fetch(`https://registry.npmjs.org/${packageName}`)
+
+  let versions = switch await result->toJson {
+  | Object(dict) =>
+    switch dict->Dict.get("versions") {
+    | Some(Object(dict)) => dict->Dict.keysToArray
+    | _ => []
+    }
+  | _ => []
+  }
+
+  let versions =
+    versions->Array.filterMap(version =>
+      version->CompareVersions.satisfies(range) ? Some(version) : None
+    )
+
+  versions->Array.reverse
+  versions
+}

src/RescriptVersions.res

@@ -5,24 +5,6 @@ let rescriptCoreVersionRange = ">=1.0.0"
 
 type versions = {rescriptVersion: string, rescriptCoreVersion: string}
 
-let getPackageVersions = async (packageName, range) => {
-  let {stdout} = await Node.Promisified.ChildProcess.exec(`npm view ${packageName} versions --json`)
-
-  let versions = switch JSON.parseExn(stdout) {
-  | Array(versions) =>
-    versions->Array.filterMap(json =>
-      switch json {
-      | String(version) if version->CompareVersions.satisfies(range) => Some(version)
-      | _ => None
-      }
-    )
-  | _ => []
-  }
-
-  versions->Array.reverse
-  versions
-}
-
 let getCompatibleRescriptCoreVersions = (~rescriptVersion, ~rescriptCoreVersions) =>
   if CompareVersions.compareVersions(rescriptVersion, "11.1.0")->Ordering.isLess {
     rescriptCoreVersions->Array.filter(coreVersion =>
@@ -38,8 +20,8 @@ let promptVersions = async () => {
   s->P.Spinner.start("Loading available versions...")
 
   let (rescriptVersions, rescriptCoreVersions) = await Promise.all2((
-    getPackageVersions("rescript", rescriptVersionRange),
-    getPackageVersions("@rescript/core", rescriptCoreVersionRange),
+    NpmRegistry.getPackageVersions("rescript", rescriptVersionRange),
+    NpmRegistry.getPackageVersions("@rescript/core", rescriptCoreVersionRange),
   ))
 
   s->P.Spinner.stop("Versions loaded.")