CSV Imports Overhaul (Transactions, Trades, Accounts, and Mint import support) (#1209)

* Remove stale 1.0 import logic and model

* Fresh start

* Checkpoint before removing nav

* First working prototype

* Add trade, account, and mint import flows

* Basic working version with tests

* System tests for each import type

* Clean up mappings flow

* Clean up PR, refactor stale code, tests

* Add back row validations

* Row validations

* Fix import job test

* Fix import navigation

* Fix mint import configuration form

* Currency preset for new accounts

test/controllers/import/uploads_controller_test.rb

@@ -0,0 +1,46 @@
+require "test_helper"
+
+class Import::UploadsControllerTest < ActionDispatch::IntegrationTest
+  setup do
+    sign_in @user = users(:family_admin)
+    @import = imports(:transaction)
+  end
+
+  test "show" do
+    get import_upload_url(@import)
+    assert_response :success
+  end
+
+  test "uploads valid csv by copy and pasting" do
+    patch import_upload_url(@import), params: {
+      import: {
+        raw_file_str: file_fixture("imports/valid.csv").read
+      }
+    }
+
+    assert_redirected_to import_configuration_url(@import)
+    assert_equal "CSV uploaded successfully.", flash[:notice]
+  end
+
+  test "uploads valid csv by file" do
+    patch import_upload_url(@import), params: {
+      import: {
+        csv_file: file_fixture_upload("imports/valid.csv")
+      }
+    }
+
+    assert_redirected_to import_configuration_url(@import)
+    assert_equal "CSV uploaded successfully.", flash[:notice]
+  end
+
+  test "invalid csv cannot be uploaded" do
+    patch import_upload_url(@import), params: {
+      import: {
+        csv_file: file_fixture_upload("imports/invalid.csv")
+      }
+    }
+
+    assert_response :unprocessable_entity
+    assert_equal "Must be valid CSV with headers and at least one row of data", flash[:alert]
+  end
+end