testflows.texts 2.0.211210.1123004

TestFlows - Texts

TestFlows-Texts

Use testflows.texts Python module to help you write auto verified software documentation by combining your text with the verification procedure of the described functionality in the same source file while leveraging the power and flexibility of TestFlows.com Open-Source Test Framework.

Source files for auto verified documentation by convention have .tfd extension and are written using Markdown. Therefore, all .tfd files are valid Markdown files. However, .tfd files are only the source files for your documentation that must be executed using tfs document run command to produce final Markdown documentation files.

$ tfs document run --input my_document.tfd --output my_document.md

• Requirements
• Installation
• Writing Auto Verified Docs
• Tutorial
• Passing Arguments
• Controlling Output Format
• Debugging Errors
• Using tfs document run

Requirements

• Python3 >= 3.8

Installation

You can install testflows.texts using pip3 command:

pip3 install --upgrade testflows.texts

After installing testflows.texts you will also have tfs command available in your environment.

Writing Auto Verified Docs

Follow the example Markdown document to get to know how you can write auto verified docs yourself.

    ## This is a heading

    This file is written using Markdown where you can have any number
    of `python:testflows` code blocks that contain executable Python code.
    
    ```python:testflows
    # This is Python code that will be executed when .tfd document is run.
    
    msg = "Hello TestFlows Texts"
    ```
 
    The scope is shared between all the code blocks in the same document.
    
    ```python:testflows
    # so `msg` variable defined above can also be accessed in this
    # `python:testflows` code block

    new_msg = msg + " Thanks for making verifying docs so easy!"
    ```
    
    The output of executing `.tfd` document using `tfs document run`
    is the final `.md` file with all the `python:testflows` code blocks
    removed and replaced with the text added to the document using
    the `text()` function.

    ```python:testflows
    # Let's use `text()` function to add some text to our document
    # dynamically in our Python code
 
    text("add this line to the final Markdown document")
    ```
    
    Any text outside the `python:testflows` code blocks are treated as Python
    f-strings. This allows you to specify expressions for substitutions.
    See [Python formatted string literals](https://docs.python.org/3/tutorial/inputoutput.html#formatted-string-literals)
    for more details.
    
    Here is an example where we will substitute the value of `msg` variable next {msg}.
    But with Python f-strings you can specify even complex expressions. For example, we can 
    convert our string in `msg` to title case as follows {msg.title()}.
    
    You can double your curly brackets to escape them when substitution expression is not needed
    using `{{` or `}}`.
    
    By the way, your document can't contain any triple quotes. If you need them then you have to
    add them using `{triple_quotes}` expression. For example,
    
    ```markdown
    This text has {triple_quotes} triple quotes.
    ```
    
    Well, this is pretty much it. With `testflows.texts` you have full power of full featured
    test framework and Python language at your disposal to make sure your documentation always
    stays upto date.

Now if you want to give it a try then save the above Markdown into test.tfd file but make sure to remove the indentation. Then you can run it as

$ tfs document run -i test.tfd -o -

and you should get the output of the final Markdown document printed to the stdout.

$ tfs document run -i test.tfd -o -
## This is a heading

This file is written using Markdown where you can have any number
of `python:testflows` code blocks that contain executable Python code.
...

Tutorial

Here a simple tutorial to introduce you to using testflows.texts.

    # TestFlows Texts Tutorial

    Let's see `testflows.texts` in action by writing auto verified
    documentation for the `-a` option of the `ls` command.

    The man page for the `ls` utility says the following:

    ```
    NAME
           ls - list directory contents

    SYNOPSIS
           ls [OPTION]... [FILE]...

    DESCRIPTION
           List  information  about  the FILEs (the current directory by default).
           Sort entries alphabetically if none of -cftuvSUX nor --sort  is  speci‐
           fied.

           Mandatory  arguments  to  long  options are mandatory for short options
           too.

           -a, --all
                  do not ignore entries starting with .
    ```

    Let's see how `-a` option works.

    First, create a file that starts with `.` using the `touch` command
    ```python:testflows
    from subprocess import run

    command = "touch .hidden_file"
    ```

    ```bash
    {command}
    ```
    ```python:testflows
    run(command, shell=True, check=True)
    # add clean up at the end of our document generation
    cleanup(run, "rm -rf .hidden_file", shell=True, check=True)
    ```

    Now we let's run
    ```python:testflows

    ls_a_command = "ls -a | grep .hidden_file"

    cmd = run(ls_a_command, shell=True, capture_output=True, text=True)

    assert cmd.returncode == 0, "returncode {cmd.returncode} is not 0"
    assert ".hidden_file" in cmd.stdout, "hidden file '.hidden_file' in not in the outout"
    ```

    ```bash
    {ls_a_command}
    ```

    and you should see our `.hidden_file` listed

    ```bash
    {cmd.stdout.strip()}
    ```

    Voilà, `ls -a` does indeed show hidden files!

Now save this source file as tutorial.tfd and execute it to produce the final Markdown file tutorial.md that we can use on our documentation site.

tfs document run -i tutorial.tfd -o tutorial.md

We know that the instructions in this article are correct as testflows.texts has executed them during writing of tutorial.md just like a technical writer would execute the commands as part of the process of writing a technical article.

Moreover, we can rerun our documentation any time a new version of ls utility is ready to be shipped to make sure our documentation is still valid and the software still behaves as described.

By the way, here is the final Markdown we get

    # TestFlows Texts Tutorial

    Let's see `testflows.texts` in action by writing auto verified
    documentation for the `-a` option of the `ls` command.

    The man page for the `ls` utility says the following:

    ```
    NAME
           ls - list directory contents

    SYNOPSIS
           ls [OPTION]... [FILE]...

    DESCRIPTION
           List  information  about  the FILEs (the current directory by default).
           Sort entries alphabetically if none of -cftuvSUX nor --sort  is  speci‐
           fied.

           Mandatory  arguments  to  long  options are mandatory for short options
           too.

           -a, --all
                  do not ignore entries starting with .
    ```

    Let's see how `-a` option works.

    First, create a file that starts with `.` using the `touch` command

    ```bash
    touch .hidden_file
    ```

    Now we let's run

    ```bash
    ls -a | grep .hidden_file
    ```

    and you should see our `.hidden_file` listed

    ```bash
    .hidden_file
    ```

    Voilà, `ls -a` does indeed show hidden files!

Passing Arguments

Execution of any .tfd file using tfs document run command results in execution of a document writer program. This is similar to the test programs you write with TestFlows.com Open-Source Testing Framework.

You can control different aspects of writer program execution by passing arguments as follows.

tfs document run -t test.tfd -o test.md -- <writer program arguments>

For example, to see all the arguments your document writer program can take pass -h/--help argument

tfs document run -- --help

Controlling Output Format

You can control output format by passing -o/--output argument to your writer program.

For example,

tfs document run -i test.tfd -o test.md -- --output classic

See -h/--help for other formats.

Debugging Errors

Here are some common errors that you might run into while writing your .tfd source files.

All exceptions will point to the line number where the error has occured.

Unescaped Curly Brackets

If you forget to double your curly brackets when you are not using f-string expression then you will see an error.

For example,

Hello there

Oops I forgot to double {quote} my curly brackets.

when executed will result in the NameError.

                10ms   ⟥⟤ Error test.tfd, /test.tfd, NameError
                         Traceback (most recent call last):
                           File "/tmp/tmp_ckk4f3m.py", line 1, in <module>
                             text(fr"""Oops I forgot to double {quote} my curly brackets.
                         NameError: name 'quote' is not defined

                         Error occured in the following text:

                           3|> Oops I forgot to double {quote} my curly brackets.

Syntax Errors

If you have a syntax error in the python:testflows block you will get an error.

For example,

    Hello there

    ```python:testflows
    x = 1
    y = 2 boo 
    ```

when executed will result in the SyntaxError.

                11ms   ⟥⟤ Error test.tfd, /test.tfd, SyntaxError
                         Traceback (most recent call last):
                           File "/home/user/.local/lib/python3.8/site-packages/testflows/texts/executable.py", line 87, in execute
                             exec(compile(source_code, source_name, 'exec'),
                         SyntaxError: invalid syntax (tmp7e6op1y_.py, line 2)

                         Syntax Error occured in the following text:

                           3|  ```python:testflows
                           4|  x = 1
                           5|> y = 2 boo 
                           6|  ```

Triple Quotes

If your text have triple quotes like """ it will result in an error.

For example,

Hello There

This text has """ triple quotes.

when executed will result in SyntaxError.

                 9ms   ⟥⟤ Error test.tfd, /test.tfd, SyntaxError
                         Traceback (most recent call last):
                           File "/home/user/.local/lib/python3.8/site-packages/testflows/texts/executable.py", line 87, in execute
                             exec(compile(source_code, source_name, 'exec'),
                         SyntaxError: invalid syntax (tmph44nbvgo.py, line 1)

                         Syntax Error occured in the following text:

                           3|> This test has """ triple quotes.

The workaround is to use {triple_quotes} expression to output """.

For example,

    Hello There

    This text has {triple_quotes} triple quotes.

where triple_quotes is provided by default by testflows.texts module. This is equivalent to the following.

    ```python:testflows
    triple_quotes = '"""'
    ```
    Hello There

    This text has {triple_quotes} triple quotes.

Using tfs document run

$ tfs document run -h
usage: tfs document run [-h] [-i path [path ...]] [-o [path]] [-f]

  ---- o o o ----
 |   o       o   |
 | 1 o 10010 o 0 |
 |   o       o   |    TestFlows.com Open-Source Software Testing Framework v1.7.211208.1222904
  ---  o o oxx --
 /           xx   \
/  ^^^        xx   \
 ------------------

Run executable document.

Executable documents are Markdown documents that
contain `python:testflows` code blocks which may contain
any Python code that will be run during document execution.  

All text within executable document except for the
`python:testflows` code blocks are treated as Python f-strings.
Therefore, you must escape any `{`, `}` characters by doubling
them, for example: `{{` or `}}`, otherwise they will be treated
as f-string expressions.

Text must not contain triple quotes `"""`. If you need them
then you must use either `text()` function within `python:testflows` code block
to explicitly add them to the the text or use `{triple_quotes}` expression. 

For example:
    ```python:testflows
    text('adding triple quotes """ to text')
    ``` 
    or

    {triple_quotes}
    

Specify '--' at the end of the command line options to pass
options to the executable document writer program itself.

For example:
   tfs document run -i <path>--o <path> -- --help

You must set PYTHONPATH when modules needed by the executable
document are not in the default path.

For example:
   PYTHONPATH=<path/to/module> tfs document run -i <path> -o <path>

The `--input` can take multiple files and in such case if `--output`
is specified it is treated as directory name.

For example,
   tfs document run -i `find $(pwd) -name "*.tfd"` -o . -f 
or
   tfs document run -i `find $(pwd) -name "*.tfd"` -o /path/to/output/dir -f 

If input is '-' (stdin) and output is '.' then output file is 'document.md'
which is created in the current working directory.

optional arguments:
  -h, --help                                   show this help message and exit
  -i path [path ...], --input path [path ...]  input file, use '-' for stdin, default: stdin
  -o [path], --output [path]                   output file or directory if multiple input files are
                                               passed, default: '.' or if input is stdin then '-'.
                                               The '.' means to create output file in the same
                                               directory as the input file having .md extension and
                                               the '-' means output to stdout.
  -f, --force                                  force to override existing output file if it already
                                               exists

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