From cd10ea03b434d54e9190bfda794d138b5778fc9d Mon Sep 17 00:00:00 2001
From: Brian Ng <bng412@gmail.com>
Date: Tue, 19 Dec 2017 10:50:01 -0600
Subject: [PATCH] Fix bug with debug output and unreleased versions

---
 packages/babel-preset-env/src/debug.js | 20 +++++++++++++++++---
 packages/babel-preset-env/src/utils.js |  2 +-
 2 files changed, 18 insertions(+), 4 deletions(-)

diff --git a/packages/babel-preset-env/src/debug.js b/packages/babel-preset-env/src/debug.js
index a1f8062b7c..4bd2855c74 100644
--- a/packages/babel-preset-env/src/debug.js
+++ b/packages/babel-preset-env/src/debug.js
@@ -1,6 +1,6 @@
 /*eslint quotes: ["error", "double", { "avoidEscape": true }]*/
 import semver from "semver";
-import { prettifyVersion, semverify } from "./utils";
+import { isUnreleasedVersion, prettifyVersion, semverify } from "./utils";
 
 const wordEnds = size => {
   return size > 1 ? "s" : "";
@@ -15,9 +15,23 @@ export const logMessage = (message, context) => {
 export const logPlugin = (plugin, targets, list, context) => {
   const envList = list[plugin] || {};
   const filteredList = Object.keys(targets).reduce((a, b) => {
-    if (!envList[b] || semver.lt(targets[b], semverify(envList[b]))) {
-      a[b] = prettifyVersion(targets[b]);
+    const version = envList[b];
+    const target = targets[b];
+
+    if (!version) {
+      a[b] = prettifyVersion(target);
+    } else {
+      const versionIsUnreleased = isUnreleasedVersion(version, b);
+      const targetIsUnreleased = isUnreleasedVersion(target, b);
+
+      if (
+        (versionIsUnreleased && !targetIsUnreleased) ||
+        (!targetIsUnreleased && semver.lt(target, semverify(version)))
+      ) {
+        a[b] = prettifyVersion(target);
+      }
     }
+
     return a;
   }, {});
 
diff --git a/packages/babel-preset-env/src/utils.js b/packages/babel-preset-env/src/utils.js
index a974e7116f..68205f05e7 100644
--- a/packages/babel-preset-env/src/utils.js
+++ b/packages/babel-preset-env/src/utils.js
@@ -58,7 +58,7 @@ export const prettifyTargets = (targets: Targets): Object => {
 export const isUnreleasedVersion = (version: string, env: string): boolean => {
   const unreleasedLabel = unreleasedLabels[env];
   return (
-    unreleasedLabel && unreleasedLabel === version.toString().toLowerCase()
+    !!unreleasedLabel && unreleasedLabel === version.toString().toLowerCase()
   );
 };