Rails, Failed assertion, no message given - ruby-on-rails

Question

When trying to write a unit test for models I keep getting the same error and cant seem to fix it.
This is my test:
require 'test_helper'
class ProductTest < ActiveSupport::TestCase
test "product attirbutes must not be empty" do
product = Product.new
assert product.invalid?
assert product.errors[:title].any?
assert product.errors[:description].any?
assert product.errors[:price].any?
assert product.errors[:image_url].any?
end
test "product price must be positive" do
product = Product.new(title: "My Book Title",
description: "yyy",
image_url: "zzz.jpg")
product.price = -1
# line number 19 below
assert product.invalid?
assert_equal ["must be greater than or equal to 0.01"],
product.errors[:price]
product.price = 0
assert product.invalid?
assert_equal ["must be greater than or equal to 0.01"],
product.errors[:price]
product.price = 1
assert product.valid?
end
end
When I run > rake test
I get the following error:
1) Failure:
ProductTest#test_product_price_must_be_positive
/test/models/product_test.rb:19]:
Failed assertion, no message given.
Here is my model:
class Product < ActiveRecord::Base
validates :title, :description, :image_url, presence: true
validates :price, numericality: {greater_then_or_equal_to: 0.01}
validates :title, uniqueness: true
validates :image_url, allow_blank: true, format: {
with: %r{\.(gif|jpg|png)\Z}i,
message: 'must be a url for GIF, JPG or PNG image.'
}
end
I have no idea what is going on here please help!

Answer 1

As per the MiniTest::Assertions docs, any method derived from 'assert' will raise the exception message "Failed assertion, no message given" on a fail unless you supply the optional 'msg' paramater
A few things:
you are testing Active Record validations, these are tried and tested, production ready features of a library so testing it is not necessary. To become more familiar with Active Record validations just go the docs and then play around with your models in the rails console
Active record validations are only performed when attempt to 'create' or 'save'
a model. For example:
my_user = User.create(name: nil, email: nil) # try save to DB - fails silently
my_user.valid? # => false
my_user.errors.messages # => {name:["can't be blank"], email:["can't be blank"]}
Maybe explore some futher learning on the topic, the Ryan Bate's screencasts are great and free for the most part. Hope this helps
Note: I hoped to attach some more links/refrences however I do not have the Stackoverflow points to do

Answer 2

your model is wrong.
(line 3)　　　　　　　　　　
　　　　　　　　　　　　　　　　　　 　　　 ↓　
wrong) validates :price, numericality: {greater_then_or_equal_to: 0.01}
　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　　
correct) validates :price, numericality: {greater_than_or_equal_to: 0.01}
not "then" but "than".