Add support for CSV content from stdin in CLI (#637)

Co-Authored-By: Étienne Barrié <[email protected]>

README.md

@@ -508,13 +508,19 @@ Alternatively, you can run your Task in the command line:
 bundle exec maintenance_tasks perform Maintenance::UpdatePostsTask
 ```
 
-To run a Task that processes CSVs from the command line, use the --csv option:
+To run a Task that processes CSVs from the command line, use the `--csv` option:
 
 ```sh-session
 bundle exec maintenance_tasks perform Maintenance::ImportPostsTask --csv "path/to/my_csv.csv"
 ```
 
-To run a Task that takes arguments from the command line, use the --arguments
+The `--csv` option also works with CSV content coming from the standard input:
+
+```sh-session
+curl "some/remote/csv" | bundle exec maintenance_tasks perform Maintenance::ImportPostsTask --csv
+```
+
+To run a Task that takes arguments from the command line, use the `--arguments`
 option, passing arguments as a set of \<key>:\<value> pairs:
 
 ```sh-session

lib/maintenance_tasks/cli.rb

@@ -1,5 +1,6 @@
 # frozen_string_literal: true
 
+require "stringio"
 require "thor"
 
 module MaintenanceTasks
@@ -27,7 +28,7 @@ def exit_on_failure?
     # Specify the CSV file to process for CSV Tasks
     desc = "Supply a CSV file to be processed by a CSV Task, "\
       "--csv path/to/csv/file.csv"
-    option :csv, desc: desc
+    option :csv, lazy_default: :stdin, desc: desc
     # Specify arguments to supply to a Task supporting parameters
     desc = "Supply arguments for a Task that accepts parameters as a set of "\
       "<key>:<value> pairs."
@@ -52,10 +53,17 @@ def perform(name)
     private
 
     def csv_file
+      return unless options.key?(:csv)
+
       csv_option = options[:csv]
-      if csv_option
+
+      if csv_option == :stdin
+        { io: StringIO.new($stdin.read), filename: "stdin.csv" }
+      else
         { io: File.open(csv_option), filename: File.basename(csv_option) }
       end
+    rescue Errno::ENOENT
+      raise ArgumentError, "CSV file not found: #{csv_option}"
     end
   end
 end

test/lib/maintenance_tasks/cli_test.rb

@@ -31,21 +31,47 @@ class CLITest < ActiveSupport::TestCase
       @cli.perform("Wrong")
     end
 
-    test "#perform runs a CSV Task with the supplied CSV when --csv option used" do
+    test "#perform runs CSV task with supplied CSV when --csv option used" do
       task = mock(name: "MyCsvTask")
       csv_file_path = file_fixture("sample.csv")
-      opened_csv_file = File.open(csv_file_path)
-      expected_attachable = { io: opened_csv_file, filename: "sample.csv" }
 
-      @cli.expects(:options).at_least_once.returns(csv: csv_file_path)
-      File.expects(:open).with(csv_file_path).returns(opened_csv_file)
       Runner.expects(:run)
-        .with(name: "MyCsvTask", csv_file: expected_attachable, arguments: {})
+        .with do |kwargs|
+          assert_equal("MyCsvTask", kwargs[:name])
+          assert_equal(csv_file_path.to_s, kwargs[:csv_file][:io].path)
+          assert_equal({}, kwargs[:arguments])
+        end
         .returns(task)
-      @cli.expects(:say_status)
-        .with(:success, "MyCsvTask was enqueued.", :green)
 
-      @cli.perform("MyCsvTask")
+      assert_output(/success\s+MyCsvTask was enqueued\./) do
+        CLI.start(["perform", "MyCsvTask", "--csv", csv_file_path])
+      end
+    end
+
+    test "#perform runs CSV task with content from stdin" do
+      task = mock(name: "MyCsvTask")
+      csv_string = "foo,bar\n1,2\n"
+      $stdin = StringIO.new(csv_string)
+
+      Runner.expects(:run)
+        .with do |kwargs|
+          assert_equal("MyCsvTask", kwargs[:name])
+          assert_equal(csv_string, kwargs[:csv_file][:io].read)
+          assert_equal({}, kwargs[:arguments])
+        end
+        .returns(task)
+
+      assert_output(/success\s+MyCsvTask was enqueued\./) do
+        CLI.start(["perform", "MyCsvTask", "--csv"])
+      end
+
+      $stdin = STDIN
+    end
+
+    test "#perform prints error message when CSV file does not exist" do
+      assert_output(/error\s+CSV file not found: foo\.csv/) do
+        CLI.start(["perform", "MyCsvTask", "--csv", "foo.csv"])
+      end
     end
 
     test "#perform runs a Task with the supplied arguments when --arguments option used" do