byexample

Write snippets of code in your documentation and execute them as regression tests.

View project on GitHub

PowerShell

byexample supports Microsoft’s PowerShell.

Run the Microsoft’s PowerShell examples calling byexample as:

$ byexample -l pwsh your-file-here                # byexample: +skip

Currently byexample only supports the version for Linux that you can install from the official site).

To run the PowerShell examples in a file you need to select pwsh as the language:

$ byexample -l pwsh docs/languages/powershell.md    # byexample: +timeout=8
<...>
[PASS] Pass: <...>

Stability: experimental - non backward compatibility changes are possible or even removal between versions (even patch versions).

New in byexample 10.1.0.

Versions tested

We tested byexample with the following versions of the language and the underlying runner or interpreter:

Language Runner/Interpreter
latest 7.2.3

Find interactive examples

For PowerShell, byexample uses the PS> string as the primary prompt and --> as the secondary prompt.

PS> $ComputerName = 'DC01', 'WEB01'

PS> foreach ($Computer in $ComputerName) {
-->    echo $Computer
--> }
DC01
WEB01

Syntax errors

Syntax errors are detected and can be part of the example. The format of the message will depend of the version of PowerShell however.

PS> echo @"this
ParserError:
Line |
   1 |  echo @"this
     |         ~
     | No characters are allowed after a here-string header but
     | before the end of the line.

Known limitations

Type text

The type feature (+type) is supported but you have to +pass the example.

In other words, you cannot check its output.

This limitation comes from PowerShell that it does not disable the echo of the terminal and what you type gets mixed with the output in unexpected/unpredictable ways.

PS> $num = Read-Host        # byexample: +input +pass
[i love 42]
PS> echo $num
i love 42

PS> $num = Read-Host num    # byexample: +input +pass
num: [i prefer 47!]
PS> echo $num
i prefer 47!

If you don’t set +pass you will get a warning.

Terminal support

To work with PowerShell, the ANSI terminal emulator is enabled by default (+term=ansi) and cannot be disabled.

Also, the terminal geometry cannot by changed after launching the interpreter so the option +geometry cannot be used in an example (but it can be used from the command line)

The amount of rows of the terminal has a minimum value of 128 and this limit is really important: if your outputs have more than 128 lines you will need to increase the geometry or the results may be undefined.

The same for the width of the terminal: minimum of 128 columns.

PowerShell specific options

$ byexample -l pwsh --show-options       # byexample: +norm-ws
<...>
pwsh's specific options
-----------------------
  None.
<...>