Add smoke test

.formatter.exs

@@ -1,4 +1,4 @@
 # Used by "mix format"
 [
-  inputs: ["{mix,.formatter}.exs", "{config,lib,test}/**/*.{ex,exs}"]
+  inputs: ["{mix,.formatter}.exs", "{bin,config,lib,test}/**/*.{ex,exs}"]
 ]

.github/workflows/test.yml

@@ -83,6 +83,9 @@ jobs:
       - name: Run tests
         run: mix test
 
+      - name: Run smoke tests
+        run: elixir ./bin/smoke_test.exs
+
       - name: Run Dialyzer
         run: mix dialyzer
         if: ${{ matrix.current_version }}

bin/smoke_test.exs

@@ -0,0 +1,114 @@
+IO.puts("Running smoke tests")
+IO.puts("\n\n")
+
+{diff, 0} = System.cmd("git", ["diff"])
+
+if diff != "" do
+  IO.puts(
+    "There are unstaged changes. Stage them (git add) or remove them for this check to be able to work."
+  )
+
+  System.halt(1)
+end
+
+IO.puts("checking smoke_test_data/project_with_formatted_code")
+
+{"", 0} = System.cmd("mix", ["format"], cd: "smoke_test_data/project_with_formatted_code")
+{diff, 0} = System.cmd("git", ["diff"], cd: "smoke_test_data/project_with_formatted_code")
+
+{"", 0} =
+  System.cmd("git", ["checkout", "--", "."], cd: "smoke_test_data/project_with_formatted_code")
+
+if diff == "" do
+  IO.puts("OK ")
+else
+  IO.puts(
+    "Expected project_with_formatted_code to be unchanged after running `mix format` in it, but there were changes:"
+  )
+
+  IO.puts(diff)
+  System.halt(2)
+end
+
+IO.puts("checking smoke_test_data/project_with_unformatted_code")
+
+{"", 0} = System.cmd("mix", ["format"], cd: "smoke_test_data/project_with_unformatted_code")
+{diff, 0} = System.cmd("git", ["diff"], cd: "smoke_test_data/project_with_unformatted_code")
+
+expected_diff =
+  """
+  diff --git a/smoke_test_data/project_with_unformatted_code/README.md b/smoke_test_data/project_with_unformatted_code/README.md
+  index d066e9b..0ccfa0b 100644
+  --- a/smoke_test_data/project_with_unformatted_code/README.md
+  +++ b/smoke_test_data/project_with_unformatted_code/README.md
+  @@ -9,9 +9,9 @@ by adding `project_with_unformatted_code` to your list of dependencies in `mix.e
+  #{" "}
+   ```elixir
+   def deps do
+  -[
+  -{ :project_with_unformatted_code, "~> 0.1.0" }
+  -]
+  +  [
+  +    {:project_with_unformatted_code, "~> 0.1.0"}
+  +  ]
+   end
+   ```
+  #{" "}
+  diff --git a/smoke_test_data/project_with_unformatted_code/docs/hello.md b/smoke_test_data/project_with_unformatted_code/docs/hello.md
+  index 114bb32..8d4ffe5 100644
+  --- a/smoke_test_data/project_with_unformatted_code/docs/hello.md
+  +++ b/smoke_test_data/project_with_unformatted_code/docs/hello.md
+  @@ -1,7 +1,7 @@
+   # Hello!
+  #{" "}
+   ~~~~elixir
+  -%{ x: 7,   y: 8}
+  +%{x: 7, y: 8}
+   ~~~~
+  #{" "}
+   [//]: # (elixir-formatter-disable-next-block)
+  @@ -11,7 +11,7 @@
+   ~~~~
+  #{" "}
+   ```elixir
+  -%{ x: 7,   y: 8}
+  +%{x: 7, y: 8}
+   ```
+  #{" "}
+   ```markdown
+  diff --git a/smoke_test_data/project_with_unformatted_code/lib/project_with_unformatted_code.ex b/smoke_test_data/project_with_unformatted_code/lib/project_with_unformatted_code.ex
+  index 7af383c..c94df7f 100644
+  --- a/smoke_test_data/project_with_unformatted_code/lib/project_with_unformatted_code.ex
+  +++ b/smoke_test_data/project_with_unformatted_code/lib/project_with_unformatted_code.ex
+  @@ -17,13 +17,14 @@ defmodule ProjectWithUnformattedCode do
+       # Hello, World!
+  #{" "}
+       ```elixir
+  -    def add(a,b), do: a+b
+  +    def add(a, b), do: a + b
+       ```
+  #{" "}
+       ```js
+       1+2+3
+       ```
+       \"""
+  +
+       :world
+     end
+   end
+  """
+
+{"", 0} =
+  System.cmd("git", ["checkout", "--", "."], cd: "smoke_test_data/project_with_unformatted_code")
+
+if diff == expected_diff do
+  IO.puts("OK")
+else
+  IO.puts(
+    "Expected project_with_unformatted_code to have specific changes after running `mix format` in it (see `bin/smoke_test.exs`), the actual changes differ:"
+  )
+
+  IO.inspect(String.myers_difference(diff, expected_diff))
+
+  System.halt(2)
+end