添加comments model测试及相关数据

test/fixtures/article_comments.yml

@@ -0,0 +1,3 @@
+article_comments:
+    id: 1
+    content: 'aaaaaaaaaaaa'

test/models/comments_model_test.rb

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+require 'test_helper'
+
+class ArticleCommentTest < ActiveSupport::TestCase
+    fixtures :article_comments 
+
+    setup do
+        @comment = ArticleComment.find(1)
+        @newcomment = ArticleComment.new
+    end
+
+    test "test_comment_create" do
+        @newcomment.content = 'bbbbbbbbbbb'
+        assert @newcomment.save
+    end
+
+    test "test_comment_read" do
+        assert_instance_of ArticleComment, @comment 
+        assert_equal 1, @comment.id, "test ArticleComment.id"
+        assert_equal "aaaaaaaaaaaa", @comment.content, "test ArticleComment.title"
+    end
+
+    test "test_comment_update" do
+        @comment.content = 'cccccccc'
+        assert @comment.save, @comment.errors.full_messages.join("; ")
+        @comment.reload
+        assert 'cccccccc', @comment.content
+    end
+
+    test "test_comment_delete" do
+        @comment.destroy
+        assert_raise(ActiveRecord::RecordNotFound) { ArticleComment.find(@comment.id) }
+    end
+end