Refactor _promptToUpdateToolchain async/await

Author: alexheretic

lib/index.js

@@ -247,47 +247,43 @@ class RustLanguageClient extends AutoLanguageClient {
   }
 
   // check for toolchain updates if installed & not dated
-  _promptToUpdateToolchain() {
+  async _promptToUpdateToolchain() {
     if (!atom.config.get('ide-rust.checkForToolchainUpdates')) return
 
     const confToolchain = configToolchain()
     const dated = confToolchain.match(DATED_REGEX)
     const toolchain = (dated ? dated[1] : confToolchain)
 
-    exec(`rustup run ${confToolchain} rustc --version`)
-      .then(({ stdout }) => fetchLatestDist({ toolchain, currentVersion: stdout }))
-      .catch(() => false)
-      .then(newVersion => {
-        if (newVersion) {
-          atom.notifications.addInfo(`Rls \`${toolchain}\` toolchain update available`, {
-            description: newVersion,
-            _src: 'ide-rust',
-            dismissable: true,
-            buttons: [{
-              text: confToolchain === toolchain ? 'Update' : 'Update & Switch',
-              onDidClick: () => {
-                clearIdeRustInfos()
-
-                const updatePromise = exec(`rustup update ${toolchain}`)
-                  // set config in case going from dated -> latest
-                  .then(() => atom.config.set('ide-rust.rlsToolchain', toolchain))
-                  .then(() => this._checkToolchain())
-                  .then(() => checkRls())
-                  .then(() => this._restartLanguageServers(`Updated Rls toolchain`))
-                  .catch(e => console.error(e))
-
-                if (this.busySignalService) {
-                  this.busySignalService.reportBusyWhile(
-                    `Updating rust \`${toolchain}\` toolchain`,
-                    () => updatePromise
-                  )
-                }
-              }
-            }]
-          })
+    let { stdout: currentVersion } = await exec(`rustup run ${confToolchain} rustc --version`)
+    let newVersion = await fetchLatestDist({ toolchain, currentVersion }).catch(() => false)
+    if (!newVersion) return
+
+    atom.notifications.addInfo(`Rls \`${toolchain}\` toolchain update available`, {
+      description: newVersion,
+      _src: 'ide-rust',
+      dismissable: true,
+      buttons: [{
+        text: confToolchain === toolchain ? 'Update' : 'Update & Switch',
+        onDidClick: () => {
+          clearIdeRustInfos()
+
+          const updatePromise = exec(`rustup update ${toolchain}`)
+            // set config in case going from dated -> latest
+            .then(() => atom.config.set('ide-rust.rlsToolchain', toolchain))
+            .then(() => this._checkToolchain())
+            .then(() => checkRls())
+            .then(() => this._restartLanguageServers(`Updated Rls toolchain`))
+            .catch(e => console.error(e))
+
+          if (this.busySignalService) {
+            this.busySignalService.reportBusyWhile(
+              `Updating rust \`${toolchain}\` toolchain`,
+              () => updatePromise
+            )
+          }
         }
-      })
-      .catch(e => console.error(e))
+      }]
+    })
   }
 
   /**