Skip to main content

Home/ Larvata/ Contents contributed and discussions participated by 張 旭

Contents contributed and discussions participated by 張 旭

Simple Middle Filter: All | Bookmarks | Topics
張 旭

Better Specs { rspec guidelines with ruby } - 0 views

www.betterspecs.org

rails ruby test programming rspec

shared by 張 旭 on 14 Jun 17 - No Cached
  • # when referring to an instance method's name
  • . (or ::) when referring to a class method's name
  • Be clear about what method you are describing.
  • ...9 more annotations...
  • When describing a context, start its description with "when" or "with".
  • is_expected.to respond_with
  • In isolated unit specs, you want each example to specify one (and only one) behavior.
  • Contexts are a powerful method to make your tests clear and well organized
  • not isolated
  • est valid, edge and invalid case.
  • new projects always use the expect syntax
  • On one line expectations or with implicit subject we should use is_expected.to
  • When you have to assign a variable instead of using a before block to create an instance variable, use let.
張 旭

Ruby on Rails 實戰聖經 | 自動化測試 - 0 views

ihower.tw/testing.html

rails test ruby programming

shared by 張 旭 on 14 Jun 17 - No Cached
  • 最小的測試粒度叫做Unit Test單元測試，會對個別的類別和方法測試結果如預期。再大一點的粒度稱作Integration Test整合測試，測試多個元件之間的互動正確。最大的粒度則是Acceptance Test驗收測試，從用戶觀點來測試整個軟體。
  • 單元測試，通常會由開發者自行負責測試，因為只有你自己清楚每個類別和方法的內部結構是怎麼設計的。
  • 哪來的時間做自動化測試呢？這個想法是相當短視和業餘的想法
  • ...18 more annotations...
  • 這其實是一種投資，如果是簡單的程式，也許你手動執行一次就寫對了，但是如果是複雜的程式，往往第一次不會寫對，你會浪費很多時間在檢查到底你寫的程式的正確性，而寫測試就可以大大的節省這些時間。更不用說你明天，下個禮拜或下個月需要再確認其他程式有沒有副作用影響的時候，你有一組測試程式可以大大節省手動檢查的時間。
  • 幾乎每種語言都有一套叫做xUnit測試框架的測試工具
  • 標準流程是 1. (Setup) 設定測試資料 2. (Exercise) 執行要測試的方法 3. (Verify) 檢查結果是否正確 4. (Teardown) 清理還原資料
  • RSpec是一套改良版的xUnit測試框架，非常風行於Rails社群
  • 個別的單元測試應該是獨立不會互相影響的
  • 一個it區塊，就是一個單元測試，裡面的expect方法會進行驗證。
  • RSpec裡，我們又把一個小單元測試叫做example
  • BDD(Behavior-driven development)測試框架，相較於TDD用test思維，測試程式的結果。BDD強調的是用spec思維，描述程式應該有什麼行為。
  • describe和context幫助你組織分類，都是可以任意套疊的。
  • 每個it就是一小段測試，在裡面我們會用expect(…).to來設定期望
  • let可以用來簡化上述的before用法，並且支援lazy evaluation和memoized，也就是有需要才初始，並且不同單元測試之間，只會初始化一次，可以增加測試執行效率
  • let!則會在測試一開始就先初始一次，而不是lazy evaluation。
  • 先列出來預計要寫的測試，或是暫時不要跑的測試
  • specify和example都是it方法的同義字。
  • 進階一點你可以自己寫Matcher
  • RSpec分成數種不同測試，分別是Model測試、Controller測試、View測試、Helper測試、Route和Request測試
  • Rails內建有Fixture功能可以建立假資料，方法是為每個Model使用一份YAML資料。
  • 記得確認每個測試案例之間的測試資料需要清除
張 旭

Rate Limits - Let's Encrypt - Free SSL/TLS Certificates - 0 views

letsencrypt.org/...rate-limits

server https security

shared by 張 旭 on 03 Jun 17 - No Cached
  • If you have a lot of subdomains, you may want to combine them into a single certificate, up to a limit of 100 Names per Certificate.
  • A certificate with multiple names is often called a SAN certificate, or sometimes a UCC certificate
  • The main limit is Certificates per Registered Domain (20 per week).
  • ...12 more annotations...
  • A certificate is considered a duplicate of an earlier certificate if they contain the exact same set of hostnames, ignoring capitalization and ordering of hostnames.
  • We also have a Duplicate Certificate limit of 5 certificates per week.
  • a Renewal Exemption to the Certificates per Registered Domain limit.
  • The Duplicate Certificate limit and the Renewal Exemption ignore the public key and extensions requested
  • You can issue 20 certificates in week 1, 20 more certificates in week 2, and so on, while not interfering with renewals of existing certificates.
  • Revoking certificates does not reset rate limits
  • If you’ve hit a rate limit, we don’t have a way to temporarily reset it.
  • get a list of certificates issued for your registered domain by searching on crt.sh
  • Revoking certificates does not reset rate limits
  • If you have a large number of pending authorization objects and are getting a rate limiting error, you can trigger a validation attempt for those authorization objects by submitting a JWS-signed POST to one of its challenges, as described in the ACME spec.
  • If you do not have logs containing the relevant authorization URLs, you need to wait for the rate limit to expire.
  • having a large number of pending authorizations is generally the result of a buggy client
張 旭

Ruby and AOP: Decouple your code even more - Arkency Blog - 0 views

blog.arkency.com/...p-decouple-your-code-even-more

ruby aop programming algorithm pattern code

shared by 張 旭 on 03 Jun 17 - No Cached
  • Dark Parts in our apps - persistence, networking, logging, notifications… these parts are scattered in our code
  • aspect-oriented programming!
  • components are parts we can easily encapsulate into some kind of code abstraction - a methods, objects or procedures.
  • ...16 more annotations...
  • application’s logic is a great example of a component
  • Aspects cross-cut our application - when we use some kind of persistence (e.g. a database) or network communication (such as ZMQ sockets) our components need to know about it.
  • Aspect-oriented programming aims to get rid of cross-cuts by separating aspect code from component code using injections of our aspects in certain join points in our component code.
  • It’s responsible for pushing snippets scenario
  • SRP-conformant object
  • the join points in Ruby
  • advice
    • 張 旭
      張 旭 on 03 Jun 17
       
      AOP 裡面的術語
  • In most cases after and before advice are sufficient.
  • what does it mean to “evaluate code around” something? In our case it means: Don’t run this method. Take it and push to my advice as an argument and evaluate this advice
  • to provide a join point
  • You’ll often see empty methods in code written in AOP paradigm
  • provide aspect code to link with our use case
  • use case is a pure domain object, without even knowing it’s connected with some kind of persistence and logging layer.
  • Aspect-oriented programming is fixing the problem with polluting pure logic objects with technical context of our applications.
  • we treat our glues as a configuration part, not the logic part of our apps.
  • Glues should not contain any logic at all
張 旭

bbatsov/rails-style-guide: A community-driven Ruby on Rails 4 style guide - 0 views

github.com/...rails-style-guide

rails programming code style

shared by 張 旭 on 07 May 17 - No Cached
  • custom initialization code in config/initializers. The code in initializers executes on application startup
  • Keep initialization code for each gem in a separate file with the same name as the gem
  • Mark additional assets for precompilation
  • ...90 more annotations...
  • config/environments/production.rb
  • Create an additional staging environment that closely resembles the production one
  • Keep any additional configuration in YAML files under the config/ directory
  • Rails::Application.config_for(:yaml_file)
  • Use nested routes to express better the relationship between ActiveRecord models
  • nest routes more than 1 level deep then use the shallow: true option
  • namespaced routes to group related actions
  • Don't use match to define any routes unless there is need to map multiple request types among [:get, :post, :patch, :put, :delete] to a single action using :via option.
  • Keep the controllers skinny
  • all the business logic should naturally reside in the model
  • Share no more than two instance variables between a controller and a view.
  • using a template
  • Prefer render plain: over render text
  • Prefer corresponding symbols to numeric HTTP status codes
  • without abbreviations
  • Keep your models for business logic and data-persistence only
  • Avoid altering ActiveRecord defaults (table names, primary key, etc)
  • Group macro-style methods (has_many, validates, etc) in the beginning of the class definition
  • Prefer has_many :through to has_and_belongs_to_many
  • self[:attribute]
  • self[:attribute] = value
  • validates
  • Keep custom validators under app/validators
  • Consider extracting custom validators to a shared gem
  • preferable to make a class method instead which serves the same purpose of the named scope
  • returns an ActiveRecord::Relation object
  • .update_attributes
  • Override the to_param method of the model
  • Use the friendly_id gem. It allows creation of human-readable URLs by using some descriptive attribute of the model instead of its id
  • find_each to iterate over a collection of AR objects
  • .find_each
  • .find_each
  • Looping through a collection of records from the database (using the all method, for example) is very inefficient since it will try to instantiate all the objects at once
  • always call before_destroy callbacks that perform validation with prepend: true
  • Define the dependent option to the has_many and has_one associations
  • always use the exception raising bang! method or handle the method return value.
  • When persisting AR objects
  • Avoid string interpolation in queries
  • param will be properly escaped
  • Consider using named placeholders instead of positional placeholders
  • use of find over where when you need to retrieve a single record by id
  • use of find_by over where and find_by_attribute
  • use of where.not over SQL
  • use heredocs with squish
  • Keep the schema.rb (or structure.sql) under version control.
  • Use rake db:schema:load instead of rake db:migrate to initialize an empty database
  • Enforce default values in the migrations themselves instead of in the application layer
  • change_column_default
  • imposing data integrity from the Rails app is impossible
  • use the change method instead of up and down methods.
  • constructive migrations
  • use models in migrations, make sure you define them so that you don't end up with broken migrations in the future
  • Don't use non-reversible migration commands in the change method.
  • In this case, block will be used by create_table in rollback
  • Never call the model layer directly from a view
  • Never make complex formatting in the views, export the formatting to a method in the view helper or the model.
  • When the labels of an ActiveRecord model need to be translated, use the activerecord scope
  • Separate the texts used in the views from translations of ActiveRecord attributes
  • Place the locale files for the models in a folder locales/models
  • the texts used in the views in folder locales/views
  • config/application.rb config.i18n.load_path += Dir[Rails.root.join('config', 'locales', '**', '*.{rb,yml}')]
  • I18n.t
  • I18n.l
  • Use "lazy" lookup for the texts used in views.
  • Use the dot-separated keys in the controllers and models
  • Reserve app/assets for custom stylesheets, javascripts, or images
  • Third party code such as jQuery or bootstrap should be placed in vendor/assets
  • Provide both HTML and plain-text view templates
  • config.action_mailer.raise_delivery_errors = true
  • Use a local SMTP server like Mailcatcher in the development environment
  • Provide default settings for the host name
  • The _url methods include the host name and the _path methods don't
  • _url
  • Format the from and to addresses properly
  • default from:
  • sending html emails all styles should be inline
  • Sending emails while generating page response should be avoided. It causes delays in loading of the page and request can timeout if multiple email are sent.
  • .start_with?
  • .end_with?
  • &.
  • Config your timezone accordingly in application.rb
  • config.active_record.default_timezone = :local
  • it can be only :utc or :local
  • Don't use Time.parse
  • Time.zone.parse
  • Don't use Time.now
  • Time.zone.now
  • Put gems used only for development or testing in the appropriate group in the Gemfile
  • Add all OS X specific gems to a darwin group in the Gemfile, and all Linux specific gems to a linux group
  • Do not remove the Gemfile.lock from version control.
張 旭

jwilder/nginx-proxy: Automated nginx proxy for Docker containers using docker-gen - 0 views

github.com/nginx-proxy

docker nginx proxy server

shared by 張 旭 on 24 Apr 17 - No Cached
  • docker-gen generates reverse proxy configs for nginx and reloads nginx when containers are started and stopped.
  • /var/run/docker.sock:/tmp/docker.sock:ro
  • Use this image to fully support HTTP/2 (including ALPN required by recent Chrome versions).
  • ...10 more annotations...
  • support multiple virtual hosts for a container
  • to connect to your backend using HTTPS instead of HTTP, set VIRTUAL_PROTO=https on the backend container.
  • The contents of /path/to/certs should contain the certificates and private keys for any virtual hosts in use.
  • to replace the default proxy settings for the nginx container, add a configuration file at /etc/nginx/proxy.conf
  • The default configuration blocks the Proxy HTTP request header from being sent to downstream servers
  • add your configuration file under /etc/nginx/conf.d using a name ending in .conf
  • If your container exposes multiple ports, nginx-proxy will default to the service running on port 80. If you need to specify a different port, you can set a VIRTUAL_PORT env var to select a different one.
  • To add settings on a per-VIRTUAL_HOST basis, add your configuration file under /etc/nginx/vhost.d
  • SNI
  • The default behavior for the proxy when port 80 and 443 are exposed is as follows: If a container has a usable cert, port 80 will redirect to 443 for that container so that HTTPS is always preferred when available. If the container does not have a usable cert, a 503 will be returned.
張 旭

Guide to Service Discovery with Docker - 0 views

docs.datadoghq.com/...servicediscovery

docker service system server dns

shared by 張 旭 on 23 Apr 17 - No Cached
  • The Service Discovery feature watches for Docker events like when a container is created, destroyed, started or stopped. When one of these happens, the Agent identifies which service is impacted, loads the configuration template for this image, and automatically sets up its checks.
  • Configuration templates can be defined by simple template files or as single key-value stores using etcd or Consul.
張 旭

The Exhaustive Guide to Rails Time Zones - Alexander Danilenko - 0 views

danilenko.org/...rails_timezones

rails programming ruby time

shared by 張 旭 on 16 Apr 17 - No Cached
  • you can use "wrong" methods in development and fairly often get valid results. But then you'll face with unexpected problems on production.
  • Ruby provides two classes to manage time: Time and DateTime
  • that's in Ruby! When it comes to Rails things get a bit more complicated
  • ...15 more annotations...
  • Rails gives your ability to configure application time zone.
  • we have 3 (!) different time zones in our application: system time, application time and database time.
  • DateTime.now and Time.now both give you the time in system time zone
  • Ruby standard library methods that know nothing about Rails time zone configuration
  • It's not Rails responsible for adding time zone, but ActiveSupport
  • switch from Time.now to Time.zone.now
  • Time.zone.now
  • no need to use it explicitly as there is shorter and more clear option.
  • Time.zone.today
  • Time.zone.local
  • Time.zone.at
  • Time.zone.parse
  • DateTime.strptime(str, "%Y-%m-%d %H:%M %Z").in_time_zone
  • always keep in mind that when you build time or date object you should respect current time zone.
  • use Time.zone instead of Time, Date or DateTime
張 旭

A Good Vimrc - 1 views

dougblack.io/...a-good-vimrc.html

vim programming development

shared by 張 旭 on 15 Apr 17 - No Cached
  • Don't put any lines in your vimrc that you don't understand.
  • the absolute worst way to make your environment better is to just copy it wholesale from others
  • adding features one by one to your vimrc aids in overall Vim comprehension
  • ...3 more annotations...
  • custom keybindings
  • Vim doesn't model undo as a simple stack. In Vim it's a tree.
  • Don't put anything in your .vimrc you don't understand!
張 旭

How to write excellent Dockerfiles - 0 views

rock-it.pl/to-write-excellent-dockerfiles

docker server system

shared by 張 旭 on 10 Apr 17 - No Cached
  • minimize image size, build time and number of layers.
  • maximize build cache usage
  • Container should do one thing
    • 張 旭
      張 旭 on 10 Apr 17
       
      這個有待商榷，在 baseimage 的 blog 介紹中有詳細的討論。
  • ...25 more annotations...
  • Use COPY and RUN commands in proper order
  • Merge multiple RUN commands into one
  • alpine versions should be enough
  • Use exec inside entrypoint script
  • Prefer COPY over ADD
  • Specify default environment variables, ports and volumes inside Dockerfile
  • problems with zombie processes
  • prepare separate Docker image for each component, and use Docker Compose to easily start multiple containers at the same time
  • Layers are cached and reused
  • Layers are immutable
  • They both makes you cry
  • rely on our base image updates
  • make a cleanup
  • alpine is a very tiny linux distribution, just about 4 MB in size.
  • Your disk will love you :)
  • WORKDIR command changes default directory, where we run our RUN / CMD / ENTRYPOINT commands.
  • CMD is a default command run after creating container without other command specified.
  • put your command inside array
  • entrypoint adds complexity
  • Entrypoint is a script, that will be run instead of command, and receive command as arguments
  • Without it, we would not be able to stop our application grecefully (SIGTERM is swallowed by bash script).
  • Use "exec" inside entrypoint script
  • ADD has some logic for downloading remote files and extracting archives.
  • stick with COPY.
  • ADD
    • 張 旭
      張 旭 on 10 Apr 17
       
      不是說要用 COPY 嗎？
張 旭

Probably Done Before: Visualizing Docker Containers and Images - 0 views

merrigrove.blogspot.tw/...ker-containers-and-images.html

docker technology system

shared by 張 旭 on 07 Apr 17 - No Cached
  •  In my opinion, understanding how a technology works under the hood is the best way to achieve learning speed and to build confidence that you are using the tool in the correct way.
  • union view
    • 張 旭
      張 旭 on 07 Apr 17
       
      把多層 image layer 串接起來，看上去就像是在讀一個 image 檔案而已。
  • The top-level layer may be read by a union-ing file system (AUFS on my docker implementation) to present a single cohesive view of all the changes as one read-only file system
  • ...36 more annotations...
  • it is nearly the same thing as an image, except that the top layer is read-write
  • A container is defined only as a read-write layer atop an image (of read-only layers itself).  It does not have to be running.
  • a running container
    • 張 旭
      張 旭 on 07 Apr 17
       
      之前一直搞錯了！不是 run 起來的才會叫 container，只要有 read-write layer 就是了！
  • the the isolated process-space and processes within
  • A running container is defined as a read-write "union view" and
  • kernel-level technologies like cgroups, namespaces
  • The processes within this process-space may change, delete or create files within the "union view" file that will be captured in the read-write layer
  • there is no longer a running container
    • 張 旭
      張 旭 on 07 Apr 17
       
      這行指令執行結束之後，running container 就停掉了，但是該 container 還在！
  • each layer contains a pointer to a parent layer using the Id
  • The 'docker create' command adds a read-write layer to the top stack based on the image id.  It does not run this container.
  • The command 'docker start' creates a process space around the union view of the container's layers.
  • can only be one process space per container.
  • the docker run command starts with an image, creates a container, and starts the container
  • 'git pull' (which is a combination of 'git fetch' and 'git merge')
  • 'docker ps' lists out the inventory of running containers on your system
  • 'docker ps -a' where the 'a' is short for 'all' lists out all the containers on your system, whether stopped or running.
  • Only those images that have containers attached to them or that have been pulled are considered top-level.
  • 'docker stop' issues a SIGTERM to a running container which politely stops all the processes in that process-space.
  • results is a normal, but non-running, container
  • 'docker kill' issues a non-polite SIGKILL command to all the processes in a running container.
  • 'docker stop' and 'docker kill' which send actual UNIX signals to a running process
  • 'docker pause' uses a special cgroups feature to freeze/pause a running process-space
  • 'docker rm' removes the read-write layer that defines a container from your host system
  • It effectively deletes files
  • 'docker rmi' removes the read-layer that defines a "union view" of an image.
  • 'docker commit' takes a container's top-level read-write layer and burns it into a read-only layer.
  • turns a container (whether running or stopped) into an immutable image
  • uses the FROM directive in the Dockerfile file as the starting image and iteratively 1) runs (create and start) 2) modifies and 3) commits.
  • At each step in the iteration a new layer is created.
  • 'docker exec' command runs on a running container and executes a process in that running container's process space
  • 'docker inspect' fetches the metadata that has been associated with the top-layer of the container or image
  • 'docker save' creates a single tar file that can be used to import on a different host system
  • only be run on an image
  • 'docker export' command creates a tar file of the contents of the "union view" and flattens it for consumption for non-Docker usages
  • This command removes the metadata and the layers.  This command can only be run on containers.
  • 'docker history' command takes an image-id and recursively prints out the read-only layers
張 旭

Transactions - RSpec Rails - RSpec - Relish - 0 views

relishapp.com/...transactions

rspec test rails programming

shared by 張 旭 on 03 Apr 17 - No Cached
  • before(:all) hooks are invoked before the transaction is opened. You can use this to speed things up by creating data once before any example in a group is run
張 旭

紀錄一下和 CORS (Cross-Origin Resource Sharing) 有關的問題 | Just for noting - 0 views

blog.m157q.tw/...cross-origin-resource-sharing

apache nginx ajax cors web server

shared by 張 旭 on 03 Apr 17 - No Cached
  • 通常只允許單一 domain
  • 回一個寫死 domain 的 Access-Control-Allow-Origin 的 HTTP Header， 但是可以在設定檔裏面做設定， 如果 request 是來自允許的 domain 的話， 就把 Access-Control-Allow-Origin 的值設定成該 domain， 如果不在白名單裡面的話當然就擋掉。
  • Google App Engine 不允許對非 static files 的 handler 加上 HTTP Headers
  • ...1 more annotation...
  • JSONP 拯救 Cross-Domain JSON API Request
張 旭

深度解读 - TDD（测试驱动开发） - 简书 - 0 views

www.jianshu.com/62f16cd4fef3

development programming test

shared by 張 旭 on 31 Mar 17 - No Cached
  • TDD的原理是在开发功能代码之前，先编写单元测试用例代码，测试代码确定需要编写什么产品代码。
  • TDD 并不能直接提高设计能力，它只是给你更多机会和保障去改善设计。
  • 写测试，只关注需求，程序的输入输出，不关心中间过程
  • ...21 more annotations...
  • 写实现，不考虑别的需求，用最简单的方式满足当前这个小需求即可
  • 一次只关注一个点，思维负担更小
  • 提前澄清需求细节
  • 写一个失败的测试，它是对一个小需求的描述，只需要关心输入输出，这个时候根本不用关心如何实现
  • 专注在用最快的方式实现当前这个小需求，不用关心其他需求，也不要管代码的质量多么惨不忍睹
  • 既不用思考需求，也没有实现的压力，只需要找出代码中的坏味道，并用一个手法消除它，让代码变成整洁的代码
  • TDD 之前要拆分任务，把一个大需求拆成多个小需求。
  • 符合 Given-When-Then 格式
  • 包含断言
  • 可以重复执行
  • 单元测试基础设施
  • 只在没有信心的地方写测试代码
  • 有注释的地方都可以抽取方法，用方法名来代替注释
  • 选一个最简单的用例，直接开写，用最简单的代码通过测试。逐渐增加测试，让代码变复杂，用重构来驱动出设计。
  • 有了重构这个工具后，做设计的压力小了很多，因为有测试代码保护，我们可以随时重构实现了
  • 在纸上迭代总比改代码要快
  • 任务分解和列 Example
  • 步子迈太大，容易扯着蛋。
  • 做探索性的技术研究（Spike），不需要长期维护，而且测试基础设施搭建成本很高，那还是手工测试吧
  • TDD 是开发人员自己的事
  • 布置完一个任务，让新人先画图，就可以在他开始写代码前对他的设计提反馈。
  • 張 旭 on 31 Mar 17
     
    "TDD的原理是在开发功能代码之前，先编写单元测试用例代码，测试代码确定需要编写什么产品代码。"
« First ‹ Previous 421 - 440 of 596 Next › Last »
Showing 20▼ items per page