From 1f79be7e4e203c7d494df21224f77e6a83d63879 Mon Sep 17 00:00:00 2001
From: Jacob Kaplan-Moss <jacob@jacobian.org>
Date: Tue, 21 Nov 2017 10:10:48 -0800
Subject: [PATCH] More error checking and docs

---
 datasette/cli.py | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/datasette/cli.py b/datasette/cli.py
index 42697c56..23fd0f15 100644
--- a/datasette/cli.py
+++ b/datasette/cli.py
@@ -30,7 +30,7 @@ def build(files, inspect_file):
 @click.argument('files', type=click.Path(exists=True), nargs=-1)
 @click.option(
     '-n', '--name', default='datasette',
-    help='Application name to use when deploying to Now'
+    help='Application name to use when deploying to Now (ignored for Heroku)'
 )
 @click.option(
     '-m', '--metadata', type=click.File(mode='r'),
@@ -47,23 +47,27 @@ def publish(publisher, files, name, metadata, extra_options, force, **extra_meta
     """
     Publish specified SQLite database files to the internet along with a datasette API.
 
-    Only current option for PUBLISHER is 'now'. You must have Zeit Now installed:
-    https://zeit.co/now
+    Options for PUBLISHER:
+        * 'now' - You must have Zeit Now installed: https://zeit.co/now
+        * 'heroku' - You must have Heroku installed: https://cli.heroku.com/
 
     Example usage: datasette publish now my-database.db
     """
-    if publisher == 'now':
-        if not shutil.which('now'):
+    def _fail_if_publish_binary_not_installed(binary, publish_target, install_link):
+        """Exit (with error message) if ``binary` isn't installed"""
+        if not shutil.which(binary):
             click.secho(
-                ' The publish command requires "now" to be installed and configured ',
+                f" Publishing to {publish_target} requires {binary} to be installed and configured ",
                 bg='red',
                 fg='white',
                 bold=True,
-                err=True,
+                err=True
             )
-            click.echo('Follow the instructions at https://zeit.co/now#whats-now', err=True)
+            click.echo(f"Follow the instructions at {install_link}", err=True)
             sys.exit(1)
 
+    if publisher == 'now':
+        _fail_if_publish_binary_not_installed('now', 'Zeit Now', 'https://zeit.co/now')
         with temporary_docker_directory(files, name, metadata, extra_options, extra_metadata):
             if force:
                 call(['now', '--force'])
@@ -71,13 +75,20 @@ def publish(publisher, files, name, metadata, extra_options, force, **extra_meta
                 call('now')
 
     elif publisher == 'heroku':
-        # FIXME: need to verify we have heroku, heroku-builds, and are logged in (ugh)
+        _fail_if_publish_binary_not_installed('heroku', 'Heroku', 'https://cli.heroku.com')
+
+        # Check for heroku-builds plugin
+        plugins = [line.split()[0] for line in check_output(['heroku', 'plugins']).splitlines()]
+        if 'heroku-builds' not in plugins:
+            click.echo('Publishing to Heroku requires the heroku-builds plugin to be installed.')
+            click.confirm('Install it? (this will run `heroku plugins:install heroku-builds`)', abort=True)
+            call(["heroku", "plugins:install", "heroku-builds"])
+
         with temporary_heroku_directory(files, name, metadata, extra_options, extra_metadata):
             create_output = check_output(['heroku', 'apps:create', '--json'])
             app_name = json.loads(create_output)["name"]
             call(["heroku", "builds:create", "-a", app_name])
 
-
 @cli.command()
 @click.argument('files', type=click.Path(exists=True), nargs=-1, required=True)
 @click.option(