diff --git a/lib/cli/src/latest_version.js b/lib/cli/src/latest_version.js
index b351f4fceb0..72e452e642d 100644
--- a/lib/cli/src/latest_version.js
+++ b/lib/cli/src/latest_version.js
@@ -1,11 +1,38 @@
 import { spawn } from 'cross-spawn';
 import { satisfies } from 'semver';
 
+/**
+ * Get latest version of the package available on npmjs.com.
+ * If constraint is set then it returns a version satisfying it, otherwise the latest version available is returned.
+ *
+ * @param {Object} npmOptions Object containing a `useYarn: boolean` attribute
+ * @param {string} packageName Name of the package
+ * @param {Object} constraint Version range to use to constraint the returned version
+ * @return {Promise<string>} Promise resolved with a version
+ */
 export function latestVersion(npmOptions, packageName, constraint) {
-  const packageManager = npmOptions.useYarn ? 'yarn' : 'npm';
+  const getPackageVersions = npmOptions.useYarn
+    ? spawnVersionsWithYarn(packageName, constraint)
+    : spawnVersionsWithNpm(packageName, constraint);
+
+  return getPackageVersions.then(versions => {
+    if (!constraint) return versions;
+
+    return versions.reverse().find(version => satisfies(version, constraint));
+  });
+}
+
+/**
+ *  Get latest version(s) of the package available on npmjs.com using NPM
+ *
+ * @param {string} packageName Name of the package
+ * @param {Object} constraint Version range to use to constraint the returned version
+ * @returns {Promise<string|Array<string>>} versions  Promise resolved with a version or an array of versions
+ */
+function spawnVersionsWithNpm(packageName, constraint) {
   return new Promise((resolve, reject) => {
     const command = spawn(
-      packageManager,
+      'npm',
       ['info', packageName, constraint ? 'versions' : 'version', '--json', '--silent'],
       {
         cwd: process.cwd(),
@@ -16,39 +43,57 @@ export function latestVersion(npmOptions, packageName, constraint) {
       }
     );
 
-    const processResult = result => {
-      if (!constraint) return result;
-
-      return result.reverse().find(version => satisfies(version, constraint));
-    };
-
     command.stdout.on('data', data => {
       try {
         const info = JSON.parse(data);
         if (info.error) {
-          // npm error
           reject(new Error(info.error.summary));
-        } else if (info.type === 'inspect') {
-          // yarn success
-          resolve(processResult(info.data));
         } else {
-          // npm success
-          resolve(processResult(info));
+          resolve(info);
         }
       } catch (e) {
-        // yarn info output
-      }
-    });
-
-    command.stderr.on('data', data => {
-      try {
-        // yarn error
-        const info = JSON.parse(data);
-        if (info.type === 'error') {
-          reject(new Error(info.data));
-        }
-      } catch (e) {
-        // package manager unstructured info/warnings output
+        reject(new Error(`Unable to find versions of ${packageName} using npm`));
+      }
+    });
+  });
+}
+
+/**
+ *  Get latest version(s) of the package available on npmjs.com using Yarn
+ *
+ * @param {string} packageName Name of the package
+ * @param {Object} constraint Version range to use to constraint the returned version
+ * @returns {Promise<string|Array<string>>} versions  Promise resolved with a version or an array of versions
+ */
+function spawnVersionsWithYarn(packageName, constraint) {
+  return new Promise((resolve, reject) => {
+    const command = spawn(
+      'yarn',
+      ['info', packageName, constraint ? 'versions' : 'version', '--json', '--silent'],
+      {
+        cwd: process.cwd(),
+        env: process.env,
+        stdio: 'pipe',
+        encoding: 'utf-8',
+        silent: true,
+      }
+    );
+
+    command.stdout.on('data', data => {
+      try {
+        const info = JSON.parse(data);
+        if (info.type === 'inspect') {
+          resolve(info.data);
+        }
+      } catch (e) {
+        reject(new Error(`Unable to find versions of ${packageName} using yarn`));
+      }
+    });
+
+    command.stderr.on('data', data => {
+      const info = JSON.parse(data);
+      if (info.type === 'error') {
+        reject(new Error(info.data));
       }
     });
   });