Refactor checkRls split & async/await

Author: alexheretic

lib/index.js

@@ -125,80 +125,74 @@ async function serverEnv(toolchain) {
   return env
 }
 
+/**
+ * Install rls-preview, rust-src, rust-analysis
+ * @param {string} toolchain
+ */
+async function installRlsComponents(toolchain) {
+  try {
+    await exec(`rustup component add rls-preview --toolchain ${toolchain}`)
+  }
+  catch (e) {
+    let suggestedVersion
+    if (toolchain.startsWith('nightly')) {
+      // 'rls-preview' not available search for a decent suggestion
+      suggestedVersion = await suggestChannelOrDated('nightly').catch(e => console.warn(e))
+    }
+    const note = {
+      detail: 'Try configuring another toolchain, like a dated nightly or `beta`',
+      dismissable: true,
+      _src: 'ide-rust',
+      buttons: [{
+        text: 'Configure',
+        onDidClick: () => atom.workspace.open('atom://config/packages/ide-rust')
+      }]
+    }
+    if (suggestedVersion) {
+      note.buttons.push({
+        text: `Use ${suggestedVersion}`,
+        onDidClick: () => atom.config.set('ide-rust.rlsToolchain', suggestedVersion)
+      })
+    }
+    atom.notifications.addError(`\`rls-preview\` was not found on \`${toolchain}\``, note)
+    throw e
+  }
+
+  try {
+    await exec(`rustup component add rust-src --toolchain ${toolchain}`)
+    await exec(`rustup component add rust-analysis --toolchain ${toolchain}`)
+  }
+  catch (e) {
+    atom.notifications.addError(`\`rust-src\`/\`rust-analysis\` not found on \`${toolchain}\``, {
+      dismissable: true
+    })
+    throw e
+  }
+}
+
 // ongoing promise
 let _checkingRls
 
 /**
  * Check for and install Rls
- * @param {BusySignalService} [busySignalService]
+ * @param {?BusySignalService} busySignalService
  * @return {Promise<*>} rls installed
  */
-function checkRls(busySignalService) {
-  let toolchain = configToolchain()
-
+async function checkRls(busySignalService) {
   if (_checkingRls) return _checkingRls
 
-  _checkingRls = exec(`rustup component list --toolchain ${toolchain}`).then(results => {
-    const { stdout } = results
+  const toolchain = configToolchain()
+  _checkingRls = (async () => {
+    let { stdout: toolchainList } = await exec(`rustup component list --toolchain ${toolchain}`)
     if (
-      stdout.search(/^rls-preview.* \((default|installed)\)$/m) >= 0 &&
-      stdout.search(/^rust-analysis.* \((default|installed)\)$/m) >= 0 &&
-      stdout.search(/^rust-src.* \((default|installed)\)$/m) >= 0
+      toolchainList.search(/^rls-preview.* \((default|installed)\)$/m) >= 0 &&
+      toolchainList.search(/^rust-analysis.* \((default|installed)\)$/m) >= 0 &&
+      toolchainList.search(/^rust-src.* \((default|installed)\)$/m) >= 0
     ) {
-      // Have RLS
-      return
+      return // have rls
     }
-
-    // Don't have RLS
-    let installRlsPromise = exec(`rustup component add rls-preview --toolchain ${toolchain}`)
-      .catch(async e => {
-        if (toolchain.startsWith('nightly')) {
-          // 'rls-preview' not available search for a decent suggestion
-          let suggestedVersion
-          try {
-            suggestedVersion = await suggestChannelOrDated('nightly')
-          } catch (e) {
-            console.warn(e)
-          }
-          if (suggestedVersion) throw [e, suggestedVersion]
-        }
-        throw [e]
-      })
-      .catch(e => {
-        let latestRlsNightly = e[1]
-
-        const note = {
-          detail: 'Try configuring another toolchain, like a dated nightly or `beta`',
-          dismissable: true,
-          _src: 'ide-rust',
-          buttons: [{
-            text: 'Configure',
-            onDidClick: () => atom.workspace.open('atom://config/packages/ide-rust')
-          }]
-        }
-        if (latestRlsNightly) {
-          note.buttons.push({
-            text: `Use ${latestRlsNightly}`,
-            onDidClick: () => atom.config.set('ide-rust.rlsToolchain', latestRlsNightly)
-          })
-        }
-
-        atom.notifications.addError(`\`rls-preview\` was not found on \`${toolchain}\``, note)
-
-        e[0]._logged = true
-        throw e[0]
-      })
-      .then(() => exec(`rustup component add rust-src --toolchain ${toolchain}`))
-      .then(() => exec(`rustup component add rust-analysis --toolchain ${toolchain}`))
-      .catch(e => {
-        if (!e._logged) {
-          atom.notifications.addError(`\`rust-src\`/\`rust-analysis\` not found on \`${toolchain}\``, {
-            dismissable: true
-          })
-        }
-        throw e
-      })
-
+    // try to install rls
+    const installRlsPromise = installRlsComponents(toolchain)
     if (busySignalService) {
       busySignalService.reportBusyWhile(
         `Adding components rls-preview, rust-src, rust-analysis`,
@@ -207,14 +201,13 @@ function checkRls(busySignalService) {
     }
 
     return installRlsPromise
-  })
+  })()
 
   try {
-    return _checkingRls
+    return await _checkingRls
   }
   finally {
-    let clearOngoing = () => _checkingRls = null
-    _checkingRls.then(clearOngoing).catch(clearOngoing)
+    _checkingRls = null
   }
 }