fix docs for fuchsia_ctl

packages/fuchsia_ctl/lib/src/dev_finder.dart

@@ -129,8 +129,11 @@ class DevFinder {
 
 /// The exception thrown when a [DevFinder] lookup fails.
 class DevFinderException implements Exception {
+  /// Creates a new [DevFinderException], such as when dev_finder fails to find
+  /// a device.
   const DevFinderException(this.message);
 
+  /// The user-facing message to display.
   final String message;
 
   @override

packages/fuchsia_ctl/lib/src/image_paver.dart

@@ -41,7 +41,7 @@ class ImagePaver {
   /// The [FileSystem] implementation used to
   final FileSystem fs;
 
-  // The implementation to use for untarring system images.
+  /// The implementation to use for untarring system images.
   final Tar tar;
 
   /// The implementation to use for creating SSH keys.

packages/fuchsia_ctl/lib/src/operation_result.dart

@@ -38,6 +38,7 @@ class OperationResult {
     return OperationResult._(false, info: info, error: error);
   }
 
+  /// Creates an [OperationResult] from a [ProcessResult].
   factory OperationResult.fromProcessResult(
     ProcessResult result, {
     int expectedExitCode = 0,

packages/fuchsia_ctl/lib/src/ssh_client.dart

@@ -25,6 +25,10 @@ class SshClient {
   /// The [ProcessManager] to use for spawning `ssh`.
   final ProcessManager processManager;
 
+  /// Creates a list of arguments to pass to ssh.
+  ///
+  /// This method is not intended for use outside of this library, except for
+  /// in unit tests.
   @visibleForTesting
   List<String> getSshArguments({
     String identityFilePath,

packages/fuchsia_ctl/lib/src/ssh_key_manager.dart

@@ -25,12 +25,21 @@ abstract class SshKeyManager {
 /// A class that delegates creating SSH keys to the system `ssh-keygen`.
 @immutable
 class SystemSshKeyManager implements SshKeyManager {
+  /// Creates a wrapper for ssh-keygen.
+  ///
+  /// The arguments must not be null, and will be used to spawn a ssh-keygen
+  /// process and manipulate the files it creates.
   const SystemSshKeyManager({
     this.processManager = const LocalProcessManager(),
     this.fs = const LocalFileSystem(),
-  });
+  })  : assert(processManager != null),
+        assert(fs != null);
 
+  /// The [ProcessManager] implementation to use when spawning ssh-keygen.
   final ProcessManager processManager;
+
+  /// The [FileSystem] implementation to use when creating the authorized_keys
+  /// file.
   final FileSystem fs;
 
   @override

packages/fuchsia_ctl/lib/src/tar.dart

@@ -16,6 +16,7 @@ abstract class Tar {
   /// A const constructor to allow subclasses to create const constructors.
   const Tar();
 
+  /// Untars a tar file.
   Future<OperationResult> untar(String src, String destination);
 }
 
@@ -30,6 +31,8 @@ class SystemTar implements Tar {
     this.processManager = const LocalProcessManager(),
   }) : assert(processManager != null);
 
+  /// The [ProcessManager] impleemntation to use when spawning the system tar
+  /// program.
   final ProcessManager processManager;
 
   @override