refactor: split shell detection from install (#15)

Author: renancaraujo

lib/install.dart

@@ -1,5 +1,5 @@
 /// Contains the functions related to the installation file
 library install;
 
-export 'src/install/install_completion.dart';
-export 'src/install/shell_completion_installation.dart';
+export 'src/install/completion_installation.dart';
+export 'src/system_shell.dart';

…stall/shell_completion_installation.dart …src/install/completion_installation.dartlib/src/install/shell_completion_installation.dart renamed to lib/src/install/completion_installation.dart lib/src/install/shell_completion_installation.dart renamed to lib/src/install/completion_installation.dart

@@ -2,55 +2,38 @@ import 'dart:io';
 
 import 'package:cli_completion/src/exceptions.dart';
 import 'package:cli_completion/src/install/shell_completion_configuration.dart';
+import 'package:cli_completion/src/system_shell.dart';
 import 'package:mason_logger/mason_logger.dart';
 import 'package:meta/meta.dart';
 import 'package:path/path.dart' as path;
 
 /// {@template shell_completion_installation}
 /// A description of a completion installation process for a specific shell.
 ///
-/// Creation should be done via [ShellCompletionInstallation.fromCurrentShell].
+/// Creation should be done via [CompletionInstallation.fromSystemShell].
 /// {@endtemplate}
-class ShellCompletionInstallation {
+class CompletionInstallation {
   /// {@macro shell_completion_installation}
   @visibleForTesting
-  ShellCompletionInstallation({
+  CompletionInstallation({
     required this.configuration,
     required this.logger,
     required this.isWindows,
     required this.environment,
   });
 
-  /// Identify the current shell and from there, create a
-  /// [ShellCompletionInstallation] with the proper
-  /// [ShellCompletionConfiguration].
-  static ShellCompletionInstallation? fromCurrentShell({
+  /// Creates a [CompletionInstallation] given the current [SystemShell].
+  factory CompletionInstallation.fromSystemShell({
+    required SystemShell systemShell,
     required Logger logger,
     bool? isWindowsOverride,
     Map<String, String>? environmentOverride,
   }) {
-    final environment = environmentOverride ?? Platform.environment;
     final isWindows = isWindowsOverride ?? Platform.isWindows;
+    final environment = environmentOverride ?? Platform.environment;
 
-    // TODO(renancaraujo): this detects the "login shell", which can be
-    // different from the actual shell.
-    final envShell = environment['SHELL'];
-    if (envShell == null || envShell.isEmpty) return null;
-
-    final basename = path.basename(envShell);
-
-    final ShellCompletionConfiguration configuration;
-    if (basename == 'zsh') {
-      configuration = zshConfiguration;
-    } else if (RegExp(r'bash(\.exe)?$').hasMatch(basename)) {
-      // on windows basename can be bash.exe
-      configuration = bashConfiguration;
-    } else {
-      return null;
-    }
-
-    return ShellCompletionInstallation(
-      configuration: configuration,
+    return CompletionInstallation(
+      configuration: ShellCompletionConfiguration.fromSystemShell(systemShell),
       logger: logger,
       isWindows: isWindows,
       environment: environment,
@@ -85,7 +68,8 @@ class ShellCompletionInstallation {
     }
   }
 
-  /// Perform the installation process.
+  /// Install completion configuration hooks for a [rootCommand] in the
+  /// current shell.
   void install(String rootCommand) {
     logger.detail(
       'Installing completion for the command $rootCommand '

lib/src/install/install_completion.dart

@@ -1,3 +1,4 @@
+import 'package:cli_completion/src/system_shell.dart';
 import 'package:meta/meta.dart';
 
 /// A type definition for functions that creates the content of a
@@ -16,14 +17,25 @@ typedef SourceStringTemplate = String Function(String scriptPath);
 @immutable
 class ShellCompletionConfiguration {
   /// {@macro shell_completion_configuration}
-  @visibleForTesting
-  const ShellCompletionConfiguration({
+  const ShellCompletionConfiguration._({
     required this.name,
     required this.shellRCFile,
     required this.sourceLineTemplate,
     required this.scriptTemplate,
   });
 
+  /// Creates a [ShellCompletionConfiguration] given the current [SystemShell].
+  factory ShellCompletionConfiguration.fromSystemShell(
+    SystemShell systemShell,
+  ) {
+    switch (systemShell) {
+      case SystemShell.zsh:
+        return zshConfiguration;
+      case SystemShell.bash:
+        return bashConfiguration;
+    }
+  }
+
   /// A descriptive string to identify the shell among others.
   final String name;
 
@@ -42,7 +54,8 @@ class ShellCompletionConfiguration {
 }
 
 /// A [ShellCompletionConfiguration] for zsh.
-final zshConfiguration = ShellCompletionConfiguration(
+@visibleForTesting
+final zshConfiguration = ShellCompletionConfiguration._(
   name: 'zsh',
   shellRCFile: '~/.zshrc',
   sourceLineTemplate: (String scriptPath) {
@@ -70,7 +83,8 @@ fi
 );
 
 /// A [ShellCompletionConfiguration] for bash.
-final bashConfiguration = ShellCompletionConfiguration(
+@visibleForTesting
+final bashConfiguration = ShellCompletionConfiguration._(
   name: 'bash',
   shellRCFile: '~/.bash_profile',
   sourceLineTemplate: (String scriptPath) {

lib/src/install/shell_completion_configuration.dart

@@ -0,0 +1,35 @@
+import 'dart:io';
+
+import 'package:path/path.dart' as path;
+
+/// The Supported shells
+enum SystemShell {
+  /// The Zsh shell: https://www.zsh.org/
+  zsh,
+
+  /// GNU Bash shell: https://www.gnu.org/software/bash/
+  bash;
+
+  /// Identifies the current shell.
+  static SystemShell? current({
+    Map<String, String>? environmentOverride,
+  }) {
+    final environment = environmentOverride ?? Platform.environment;
+
+    // TODO(renancaraujo): this detects the "login shell", which can be
+    // different from the actual shell.
+    final envShell = environment['SHELL'];
+    if (envShell == null || envShell.isEmpty) return null;
+
+    final basename = path.basename(envShell);
+
+    if (basename == 'zsh') {
+      return SystemShell.zsh;
+    } else if (RegExp(r'bash(\.exe)?$').hasMatch(basename)) {
+      // on windows basename can be bash.exe
+      return SystemShell.bash;
+    }
+
+    return null;
+  }
+}