testflows.texts 2.0.211217.1011222

Description:

testflows.texts 2.0.211217.1011222

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)
```

Let's now 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
```

Let's now 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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