[firehose] Set exit code and return instead of calling exit(X) (#341)

pkgs/firehose/CHANGELOG.md

diff --git a/pkgs/firehose/CHANGELOG.md b/pkgs/firehose/CHANGELOG.md
index ef1ba43..4988a36 100644
--- a/pkgs/firehose/CHANGELOG.md
+++ b/pkgs/firehose/CHANGELOG.md
@@ -1,3 +1,5 @@
+## 1.0.0-wip
+
 ## 0.10.2
 
 - Don't check licenses of generated files in PR health workflow.

pkgs/firehose/bin/firehose.dart

diff --git a/pkgs/firehose/bin/firehose.dart b/pkgs/firehose/bin/firehose.dart
index 82bb7dd..247df00 100644
--- a/pkgs/firehose/bin/firehose.dart
+++ b/pkgs/firehose/bin/firehose.dart
@@ -20,7 +20,7 @@
 
     if (argResults[helpFlag] as bool) {
       _usage(argParser);
-      exit(0);
+      return;
     }
 
     final validate = argResults[validateFlag] as bool;
@@ -34,7 +34,8 @@
     if (!validate && !publish) {
       _usage(argParser,
           error: 'Error: one of --validate or --publish must be specified.');
-      exit(1);
+      exitCode = 1;
+      return;
     }
 
     final github = GithubApi();
@@ -42,7 +43,8 @@
       _usage(argParser,
           error: 'Error: --publish can only be executed from within a GitHub '
               'action.');
-      exit(1);
+      exitCode = 1;
+      return;
     }
 
     final firehose = Firehose(Directory.current, useFlutter, ignoredPackages);
@@ -54,7 +56,8 @@
     }
   } on ArgParserException catch (e) {
     _usage(argParser, error: e.message);
-    exit(1);
+    exitCode = 1;
+    return;
   }
 }
 

pkgs/firehose/pubspec.yaml

diff --git a/pkgs/firehose/pubspec.yaml b/pkgs/firehose/pubspec.yaml
index 3198949..dde1a03 100644
--- a/pkgs/firehose/pubspec.yaml
+++ b/pkgs/firehose/pubspec.yaml
@@ -1,6 +1,6 @@
 name: firehose
 description: A tool to automate publishing of Pub packages from GitHub actions.
-version: 0.10.2
+version: 1.0.0-wip
 repository: https://github.com/dart-lang/ecosystem/tree/main/pkgs/firehose
 
 environment: