Fix a bug that causes an error when $ rebar3 help efmt is executed

.github/workflows/ci.yml

@@ -80,3 +80,13 @@ jobs:
         with:
           command: clippy
           args: --all -- -D warnings
+
+  plugin-test:
+    name: rebar3 plugin test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - run: rebar3 help efmt
+        working-directory: rebar3_efmt/test/foo
+      - run: rebar3 efmt -w
+        working-directory: rebar3_efmt/test/foo

rebar3_efmt/src/rebar3_efmt_prv.erl

@@ -69,7 +69,7 @@ opts() ->
       "(note that files spcified by `.gitignore` will be ignored)"},
      {disable_update_check, undefined, "disable-update-check", undefined,
       "Stops issuing an HTTP GET request each command execution to check if a newer version has been released"},
-     {allow_partial_failure, "allow-partial-failure", undefined,
+     {allow_partial_failure, undefined, "allow-partial-failure", undefined,
       "Don't raise an error even if the input contains wrong Erlang code."
       "`efmt` tries to continue formatting the remaining part of the code as much as possible"}
     ].

rebar3_efmt/test/foo/.gitignore

@@ -0,0 +1,19 @@
+.rebar3
+_*
+.eunit
+*.o
+*.beam
+*.plt
+*.swp
+*.swo
+.erlang.cookie
+ebin
+log
+erl_crash.dump
+.rebar
+logs
+_build
+.idea
+*.iml
+rebar3.crashdump
+*~

rebar3_efmt/test/foo/_checkouts/rebar3_efmt

@@ -0,0 +1 @@
+../../../

rebar3_efmt/test/foo/rebar.config

@@ -0,0 +1,3 @@
+{erl_opts, [debug_info]}.
+{project_plugins, [rebar3_efmt]}.
+{deps, []}.

rebar3_efmt/test/foo/src/foo.app.src

@@ -0,0 +1,14 @@
+{application, foo,
+ [{description, "An OTP library"},
+  {vsn, "0.1.0"},
+  {registered, []},
+  {applications,
+   [kernel,
+    stdlib
+   ]},
+  {env,[]},
+  {modules, []},
+
+  {licenses, ["Apache 2.0"]},
+  {links, []}
+ ]}.

rebar3_efmt/test/foo/src/foo.erl

@@ -0,0 +1,3 @@
+-module(foo).
+
+-export([]).