测试文件通常带 `.t` 后缀,以此跟源码树中的其他文件相区分。每个测试文件本身是一个 Perl 脚本。

== Test File Layout

// 翻译中。。。。(luozexuan) :special_data_line: DATA

Test files usually have a common file extension, .t, to distinguish themselves from other types of files in the source tree. Each test file is a Perl script per se. Test::Nginx follows a special design that decomposes each test file into two main parts: the first part is a very short prologue that consists of a few lines of Perl code while the second part is a listing of the test cases in a special data format. These two parts are separated by the following special line

测试文件通常带 .t 后缀,以此跟源码树中的其他文件相区分。每个测试文件本身是一个 Perl 脚本。 Test::Nginx 遵循一套特别的设计,把每个测试文件分成两部分: 第一部分是非常短的序言(prologue),包括若干行 Perl 代码; 第二部分则是按特定格式组织起来的测试用例列表。 这两部分由下面这一行分隔开来。

…. DATA ….

The perl interpreter or the prove utility stop interpreting the file content as Perl source code until they see this special line. Everything after this line is treated as data in plain text that is reachable by the Perl code above this line. The most interesting part of each .t test file is the stuff after this line, i.e., the data part.

perl 解释器或 prove 工具一旦遇到这一行,就会停止以 Perl 代码的形式解释文件内容。 在这之后的文本,都会被当作前面的 Perl 代码所能操作的 数据 。 这部分,即数据部分,是每个 .t 测试文件中最有趣的地方,

NOTE: The special {special_data_line} notation is a powerful feature of the Perl programming language that allows embedding arbitrary free-text data in any Perl script files that can be manipulated by the containing Perl scripts themselves. Test::Nginx takes advantage of this feature to allow data-driven test case specifications in a simple format or language that is easily understandable by everyone, even those without any prior experiences in Perl programming.

NOTE: {special_data_line} 标记是 Perl 编程语言的一个强大特性, 它允许你添加任意纯文本数据到 Perl 脚本文件中, 以供该脚本使用。 凭借这一特性,Test::Nginx 实现了一套简单的测试格式,亦可说是语言。 用户无需学习 Perl, 即可上手编写简明易懂的数据驱动的测试用例。

=== The Prologue Part 序言部分

The first part, i.e., the “prologue” above the {special_data_line} line is usually just a few lines of Perl code. You do not have to know Perl programming to write them down because they are so simple and seldom or never change. The simplest Perl code prologue is as follows:

第一部分,即位于 {special_data_line} 之上的“序言部分”,通常只是寥寥几行 Perl 代码。 这些代码是如此地简单和通用,以至于不需要懂 Perl 语法就能编写。最简单的 Perl 序言如下:


use Test::Nginx::Socket ‘no_plan’; run_tests(); —-

The first line is just loading the Perl module (or class), Test::Nginx::Socket and passing the option 'no_plan' to it to disable test plans (we will talk more about test plans in later chapters and we do not bother worrying about it here). Test::Nginx::Socket is one of the most popular class in the Test::Nginx test framework. The second line just calls the run_tests Perl function imported automatically from the Test::Nginx::Socket module to run all the test cases defined in the data part of the test file (i.e., the things coming after the {special_data_line} line).

这里的第一行加载了 Perl 模块(或类)——Test::Nginx::Socket 并传递 'no_plan' 参数来禁用测试计划(test plan,我们后面会提到更多关于它的内容,这里先搁置不管)。 Test::Nginx::SocketTest::Nginx 测试框架中最常用的类之一。 第二行调用了从 Test::Nginx::Socket 模块中自动引入的 run_tests 来运行测试文件中定义的所有测试用例(即 {special_data_line} 之后的内容)。

There are, however, more complicated prologue parts in many real-world test suites. Such prologues usually define some special environment variables or Perl variables that can be shared and referenced in the test cases defined in the “data part”, or just call some other Perl functions imported by the Test::Nginx::Socket module to customize the testing configurations and behaviors for the current test file. We will return to such fancier prologues in later sections. They can be very helpful in some cases.

在实际的测试代码中,序言部分的内容往往会更加复杂。 这些内容包括定义能在各个用例中共享的环境变量或 Perl 变量,或者调用 Test::Nginx::Socket 模块中的函数来自定义当前测试文件的配置和行为。 在后面的段落中,我们会回过头介绍这些序言。在某些场景下,它们真的挺有用。

NOTE: Perl allows function calls to omit the parentheses if the context is unambiguous. So we may see Perl function calls without parentheses in real-world test files’ prologue part, like run_tests;. We may use such forms in examples presented in later sections because they are more compact.

NOTE: 在上下文不引起歧义的情况下,Perl 允许在调用函数时省略括号。 所以在实际项目中的测试文件的序言部分,我们能够看到省略括号的用法,比如 run_tests;。 在接下来的段落中,我们会使用这种形式,因为它让代码更紧凑。

=== The Data Part 数据部分

The data part is the most important part of any test files powered by Test::Nginx. This is where test cases reside. It uses a simple specification format to express test cases so that the user does not use Perl or any other general-purpose languages to present the tests themselves. This special specification format is an instance of Domain-Specific Languages (DSL) where the “domain” is defined as testing code running upon or inside NGINX. Use of a DSL to present test cases open the door of presenting the test cases as data instead of code. This is also why Test::Nginx is a data-driven testing framework.

数据部分是 Test::Nginx 测试文件中最为重要的部分。这是测试用例所在之处。 它设计了一种简单的数据格式,让用户无需使用 Perl 或其他通用语言来撰写测试用例。 这种特别的专用格式适用于为运行在NGINX上的代码编写测试这一领域,算是领域特定语言(DSL)的一种。 DSL的使用打开了新世界的大门,使得用户可以把测试用例当作 数据 而非代码。 这也是为什么 Test::Nginx 是一个数据驱动的测试框架。

The test case specification in the data part is composed by a series of test blocks. Each test block usually corresponds to a single test case, which has a title, an optional description, and a series of data sections. The structure of a test block is described by the following template.

测试用例在数据部分由一组 测试块 构成。 每个测试块对应单个策划是用例,包含一个 标题 、一个可选的 描述 和几个 数据节。 下面的模板描述了一个测试块的结构:


=== title optional description goes here… — section1 value1 goes here — section2 value2 is here — section3 value3 —-

==== Block Titles 块标题

As we can see, each test block starts with a title line prefixed by three equal sign (===). It is important to avoid any leading spaces at the beginning of the line. The title is mandatory and is important to describe the intention of the current test case in the most concise form, and also to identify the test block in the test report when test failures happen. By convention we put a TEST N: prefix in this title, for instance, TEST 3: test the simplest form. Don’t worry about maintaining the test ordinal numbers in these titles yourself, we will introduce a command-line utility called link:[reindex] in a later section that can automatically update the ordinal numbers in the block titles for you.

如你所见,每个测试块的标题以三个等于号(===)作为开头。注意行头 不能 留空。 标题是必须要有的,你需要在此用精炼的语言描述当前测试用例的意图。 当测试失败时,你还需要靠它定位具体的测试块。简明起见,我们会给标题加上一个 TEST N: 前缀, 比如 TEST3: test the simplest form。 无需担心测试序号的维护问题,我们稍后会介绍一个名为 link:[reindex] 的命令行工具,它会替你自动更新块标题的序号。

==== Block Descriptions 块描述

Each test block can carry an optional description right after the block title line. This description can span multiple lines if needed. It is a more detailed description of the intention of the test block than the block title and may also give some background information about the current test. Many test cases just omit this part for convenience.

每个测试块可以在块标题下面加上可选的块描述。如果需要的话,这个描述可以分成多行。 比起块标题,它更加详尽地说明了测试块的意图,还可能提供当前测试的一些背景信息。 出于方便,许多测试用例省略了这一部分。

==== Data Sections 数据节

Every test block carries one or more data sections right after the block description (if any). Data sections always have a name and a value, which specify any input data fields and the expected output data fields.

(如果有的话)块描述后面紧接着一到多个 数据节。 数据节总是带有一个名字和对应值,指定输入的数据类型和 期望的 输出数据类型。

The name of a data section is the word after the line prefix ---. Spaces are allowed though not syntactically required after ---. We usually use a single space between the prefix and the section name for aesthetic considerations and we hope that you follow this convention as well. The section names usually contain just alphanumeric letters and underscore characters.

一个数据节的名字指 --- 前缀后面的文字。--- 后面可以带空格,尽管这不是语法上的要求。 出于美观起见,我们通常在前缀和名字间留出一个空格,也希望你能照着做。 数据节的名字通常只由字母、数字和下划线组成。

Section values are specified in two forms. One is all the lines after the section name line, before the next section or the next block. The other form is more concise and specifies the value directly on the same line as the section name, but right after the first colon character (:). The latter form requires that the value contains no line-breaks. Any spaces around the colon are always discarded and never count as a part of the section value; furthermore, the trailing line-break character in the one-line form does not count either.

数据节的值有两种表现形式。一种是名字那一行之后、下一数据节或测试块之前的各行。 另一种形式更为紧凑,你可以直接在名字的同一行,以冒号(:)隔开指定值。 前提是指定的值只有一行。冒号两边的空格会被忽略,不作为值的一部分;另外,行结尾的换行符也不会算入。

If no visible values come after the section name in either form, then the section takes an empty string value, which is still a defined value, however. On the other hand, omitting the section name (and value) altogether makes that section undefined.

如果名字之后不带任何可见的值,该数据节的值为空字符串,这依然算一个 有定义 的值。 但是,如果某个数据节没有名字(也没值),那么它是 未定义 的。

Test::Nginx offers various pre-defined data section names that can be used in the test blocks for different purposes. Some data sections are for specifying input data, some are for expected output, and some for controlling whether the current test block should be run at all.

Test::Nginx 预先定义了一些在测试块中有特殊用途的数据节名。 有些数据节用来指定输入数据,有些用来指定期望的输出,还有些用来标记当前测试块是否需要运行。

It is best to explain data sections in a concrete test block example.



=== TEST 1: hello, world This is just a simple demonstration of the echo directive provided by ngx_http_echo_module. ngx_http_echo_module 提供的 echo 指令的一个简单演示。 — config location = /t { echo “hello, world!”; } — request GET /t — response_body hello, world! — error_code: 200 —-

Here we have two input data sections, config and request, for specifying a custom NGINX configuration snippet in the default server {} and the HTTP request sent by the test scaffold to the test NGINX server, respectively. In addition, we have one output data section, response_body, for specifying the expected response body output by the test NGINX server. If the actual response body data is different from what we specify under the response_body section, this test case fails. We have another output data section, error_code, which specifies its value on the same line of the section name. We see that a colon character is used to separate the section name and values. Obviously, the error_code section specifies the expected HTTP response status code, which is 200.

这里有两个关于输入的数据节,configrequest。 前者自定义 server {} 内的 NGINX 配置,后者指定测试脚手架发给 NGINX 服务器的 HTTP 请求。 另外,还有一个关于输出的数据节——response_body,指定测试时期望 NGINX 返回的响应。 如果实际上的响应不同于 response_body 的值,该测试用例就失败。 我们还有另外一个关于输出的数据节——error_code,它的值和名字都在同一行。 可以看到,数据节的名字和值之间以冒号隔开。 显而易见,error_code数据节所指定的,是期望的 HTTP 响应状态码——在这里是200。

Empty lines around data sections are always discarded by Test::Nginx::Socket. Thus the test block above can be rewritten as below without changing its meaning.

数据节前后的空行会被 TEST::Nginx::Socket 忽略掉。 所以上面的测试块示例可以重写成下面的样子:


=== TEST 1: hello, world This is just a simple demonstration of the echo directive provided by ngx_http_echo_module. ngx_http_echo_module 提供的 echo 指令的一个简单演示。

— config location = /t { echo “hello, world!”; }

— request GET /t

— response_body hello, world!

— error_code: 200

Some users prefer this style for aesthetic reasons. We are free to choose whatever form you like.


There are also some special data sections that specify neither input nor output. They are just used to control how test blocks are run. For example, the ONLY section makes only the current test block in the current test file run and all the other test blocks are skipped. This is extremely useful for running an individual test block in any given file, which is a common requirement while debugging a particular test failure. Also, the special SKIP section can skip running the containing test block unconditionally, handy for preparing test cases for future features without introducing any expected test failures. We will visit more such “control sections” in later sections.

有些特殊的数据节跟输入和输出都没有关系。它们只用于 控制 测试块运行的方式。 举个例子, ONLY 数据节仅让所在的测试块运行,跳过当前测试文件的其他测试块。 在调试某个失败的测试时,使用该数据节仅运行单一的测试块,是个很实用的方法。 另一个特殊的数据节 SKIP 可以无条件地跳过所在的测试块。 在准备针对待开发特性的测试时,你可以先用该数据节避免意料之中的测试错误。 稍后我们会介绍更多类似这样的“控制数据节”。

We shall see, in a later section, that the user can define her own data sections or extending existing ones by writing a little bit of custom Perl code to satisfy her more complicated testing requirements.

在下文我们还会提到,用户可以通过编写 Perl 代码自定义数据节或拓展现有数据节来满足自己复杂的测试要求。

==== Section Filters 节过滤器

Data sections can take one or more filters. Filters are handy when you want to adjust or convert the section values in certain ways.

一个数据节可以有一到多个 过滤器。过滤器可以用来调整或者转换数据节的值。

Syntactically, filters are specified right after the section name with at least one space character as the separator. Multiple filters are also separated by spaces and are applied in the order they are written.

过滤器放在数据节名字的后面,并至少用一个空格隔开。多 个过滤器之间以空格隔开,并按代码中的顺序依次调用。

Test::Nginx::Socket provides many filters for your convenience. Consider the following data section from the aforementioned test block.

Test::Nginx::Socket 提供了许多常用的过滤器。看下来自前述测试块的一个数据节:


— error_code: 200 —-

If we want to place the section value, 200, in a separate line, like below,



— error_code 200 —-

then the section value would contain a trailing new line, which leads to a test failure. This is because the one-line form always excludes the trailing new-line character while the multi-line form always includes one. To explicitly exclude the trailing new-line in the multi-line form, we can employ the chomp filter, as in

那么数据节的值里就会有一个换行符,导致状态码无法匹配。 这是因为单行模式的值会移除结尾的换行符,而多行模式不会。要想在多行模式里去掉结尾的换行,我们可以采用 chomp 过滤器,像这样


— error_code chomp 200 —-

Now it has exactly the same semantics as the previous one-line form.


Some filters have more dramatic effect on the section values. For instance, the eval filter evaluates the section value as arbitrary Perl code, and the Perl value resulted from the execution will be used as the final section value. The following section demonstrates using the eval filter to produce 4096 a’s:

有些过滤器效果更加显著。 比如,eval 过滤器会把给定的值当作 Perl 代码执行,返回执行结果作为最终的值。 下面的数据节示范如何用 eval 过滤器生成4096个‘a’:


— response_body eval “a” x 4096 —-

The original value of the response_body section above is a Perl expression where the x symbol is a Perl operator is used to construct a string that repeats the string specified as the left-hand-side N times where N is specified by the right-hand-side. The resulting 4096-byte Perl string after evaluating this expression dictated by the eval filter will be used as the final section value for comparison with the actual response body data. It is obvious that use of the eval filter and a Perl expression here is much more readable and manageable by directly pasting that 4096-byte string in the test block.

response_body 数据节原来的值是一个 Perl 表达式,其中 x 运算符会把左边的字符串重复 N 次,N是它右边的数字。 eval 返回的包含4096个字符的 Perl 字符串会被用作数据节最终的值,跟响应体作比较。 显而易见,无论从可读性还是从可维护性上看,使用 eval 过滤器和一个 Perl 表达式要比直接贴上4096个字符更胜一筹。

As with data sections, the user can also define her own filters, as we shall see in a later section.


=== A Complete Example 一个完整的例子

We can conclude this section by a complete test file example given below, with both the prologue part and the data part.



use Test::Nginx::Socket ‘no_plan’;



=== TEST 1: hello, world This is just a simple demonstration of the echo directive provided by ngx_http_echo_module. ngx_http_echo_module 提供的 echo 指令的一个简单演示。 — config location = /t { echo “hello, world!”; } — request GET /t — response_body hello, world! — error_code: 200 —-

We will see how to actually run such test files in the next section.


NOTE: The test file layout described in this section is exactly the same as the test files based on other test frameworks derived from Test::Base, the superclass of Test::Nginx::Socket, except those specialized test sections and specialized Perl functions defined only in Test::Nginx::Socket. All the Test::Base derivatives share the same basic layout and syntax. They proudly inherit the same veins of blood.

NOTE: 本节中描述的测试文件布局跟其他基于 TEST::BaseTest::Nginx::Socket 的父类)的测试框架的几乎一样,除了一些特殊的数据节和仅在 Test::Nginx::Socket 定义的 Perl 函数。所有衍生自 Test::Base 的框架都继承了相同的基本布局和语法。毕竟它们本是同根生。