add better example for heroku deploy script

tests/examples.rs

@@ -42,3 +42,4 @@ macro_rules! example {
 
 example!(simple);
 example!(bigger);
+example!(heroku_deploy);

tests/examples/heroku_deploy/expected

@@ -0,0 +1 @@
+All tests passed.

tests/examples/heroku_deploy/script

@@ -0,0 +1,19 @@
+#!/usr/bin/env bash
+
+if [ -z "$1" ] ; then
+  echo please, pass in the heroku app as an argument 1>&2
+  exit 1
+fi
+
+if [ -n "$(git status --porcelain)" ] && [ "$2" != "--force" ] ; then
+  echo exiting, git repo not clean 1>&2
+  exit 1
+fi
+
+if ! cargo test ; then
+  echo exiting, tests don\'t pass 1>&2
+  exit 1
+fi
+
+heroku container:push web --app "$1"
+heroku container:release web --app "$1"

tests/examples/heroku_deploy/script.test.yaml

@@ -0,0 +1,39 @@
+tests:
+  # exits when the git repo is not clean
+  - arguments: test-heroku-app
+    steps:
+      - command: git status --porcelain
+        stdout: " M some-changed-file\n"
+    stderr: "exiting, git repo not clean\n"
+    exitcode: 1
+
+  # exits and prints a usage message when no arguments given
+  - steps: []
+    stderr: "please, pass in the heroku app as an argument\n"
+    exitcode: 1
+
+  # exits when the tests don't pass
+  - arguments: test-heroku-app
+    steps:
+      - git status --porcelain
+      - command: cargo test
+        exitcode: 1
+    stderr: "exiting, tests don't pass\n"
+    exitcode: 1
+
+  # builds and deploys to heroku
+  - arguments: test-heroku-app
+    steps:
+      - git status --porcelain
+      - cargo test
+      - heroku container:push web --app test-heroku-app
+      - heroku container:release web --app test-heroku-app
+
+  # allows to force deploying of dirty git repo
+  - arguments: test-heroku-app --force
+    steps:
+      - command: git status --porcelain
+        stdout: " M some-changed-file\n"
+      - cargo test
+      - heroku container:push web --app test-heroku-app
+      - heroku container:release web --app test-heroku-app