upgrade message

Signed-off-by: Kenneth Reitz <me@kennethreitz.org>

Pipfile

@@ -12,6 +12,7 @@ pep8 = "*"
 pytest = "*"
 pip-tools = "*"
 background = "*"
+semver = "*"
 
 [requires]
 python_version = "3.6"

Pipfile.lock

@@ -1,7 +1,7 @@
 {
     "_meta": {
         "hash": {
-            "sha256": "bd2336c28dabc3c3cadf760e0f49a28b6403e13ff6d2623694879836fe29e56b"
+            "sha256": "38b59dc070cded14f6a19f827b3423f34761232e0563da9e0c733e650bc0423c"
         },
         "pipfile-spec": 1,
         "requires": {
@@ -72,6 +72,9 @@
         "resumable-urlretrieve": {
             "version": "==0.1.5"
         },
+        "semver": {
+            "version": "==2.7.8"
+        },
         "six": {
             "version": "==1.10.0"
         },

pipenv/cli.py

@@ -8,6 +8,7 @@ import distutils.spawn
 import shutil
 import signal
 
+import background
 import click
 import click_completion
 import crayons
@@ -16,6 +17,7 @@ import parse
 import pexpect
 import requests
 import pipfile
+import semver
 from blindspin import spinner
 from requests.packages.urllib3.exceptions import InsecureRequestWarning
 
@@ -60,6 +62,21 @@ requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
 
 project = Project()
 
+@background.task
+def check_for_updates():
+    try:
+        r = requests.get('https://pypi.python.org/pypi/pipenv/json')
+        latest = sorted([semver.parse_version_info(v) for v in list(r.json()['releases'].keys())])[-1]
+        current = semver.parse_version_info(__version__)
+
+        if latest > current:
+            click.echo('{0}: {1} is now available. You get bonus points for upgrading!'.format(
+                crayons.green('Courtesy Notice'),
+                crayons.yellow('Pipenv v{v.major}.{v.minor}.{v.patch}'.format(v=latest)),
+            ), err=True)
+    except Exception:
+        pass
+
 
 def cleanup_virtualenv(bare=True):
     """Removes the virtualenv directory from the system."""
@@ -790,6 +807,8 @@ def easter_egg(package_name):
 @click.pass_context
 def cli(ctx, where=False, venv=False, rm=False, bare=False, three=False, python=False, help=False):
 
+    check_for_updates()
+
     if ctx.invoked_subcommand is None:
         # --where was passed...
         if where: