numd

reproducible Nushell Markdown documents

Execute blocks of nushell code within markdown documents, write results back to your .md document, or output them to the terminal.

numd is inspired by R Markdown.

Quickstart

# this block won't run as it has the option `no-run` in its code fence
> git clone https://github.com/nushell-prophet/numd; cd numd
> nupm install --force --path . # optionally you can install this module via nupm
> use numd
> numd run README.md --no-save

How it works

numd run parses the initial file (example), generates a script to execute the found commands (example), executes this script in a new nushell instance, captures the results, updates the initial document accordingly, and/or outputs the resulting document into the terminal along with basic changes stats.

Experienced nushell users can understand the logic better by looking at examples. Especially, seeing numd in action describing its own commands.

Details on parsing code blocks and displaying the output

1. numd looks for code blocks marked with ```nushell or ```nu.
2. In code blocks that do not contain any lines starting with the > symbol, numd executes the entire code block as is. If the code produces any output, the output is added next to the code block after an empty line, a line with the word Output:, and another empty line. The output is enclosed in code fences without a language identifier.
3. In code blocks that contain one or more lines starting with the > symbol, numd filters only lines that start with the > or # symbol. It executes or prints those lines one by one, and outputs the results immediately after the executed line.

numd run flags and params

> use numd
> numd run --help | numd parse-help
// Description:
//   Run Nushell code blocks in a markdown file, output results back to the `.md`, and optionally to terminal
//
//
// Usage:
//   > run {flags} <file>
//
//
// Flags:
//   -o, --result-md-path <path>: path to a resulting `.md` file; if omitted, updates the original file
//   --print-block-results: print blocks one by one as they are executed
//   --echo: output resulting markdown to the terminal
//   --save-ansi: save ANSI formatted version
//   --no-backup: overwrite the existing `.md` file without backup
//   --no-save: do not save changes to the `.md` file
//   --no-stats: do not output stats of changes
//   --intermed-script <path>: optional path for keeping intermediate script (useful for debugging purposes). If not set, the temporary intermediate script will be deleted.
//   --no-fail-on-error: skip errors (and don't update markdown in case of errors anyway)
//   --prepend-code <string>: prepend code into the intermediate script, useful for customizing Nushell output settings
//   --table-width <int>: set the `table --width` option value
//   --config-path <path>: path to a config file (default: '')
//
//
// Parameters:
//   file <path>: path to a `.md` file containing Nushell code to be executed
//
//
// Input/output types:
//   ╭─#─┬──input──┬─output──╮
//   │ 0 │ nothing │ string  │
//   │ 1 │ nothing │ nothing │
//   │ 2 │ nothing │ record  │
//   ╰─#─┴──input──┴─output──╯

Supported nushell code block options

numd understands the following block options. Several comma-separated block options will be combined together. The block options should be in the infostring of the opening code fence like the example: ```nushell try, new-instance

> numd list-code-options --list
╭─────long──────┬─short─┬───────────────────────────description───────────────────────────╮
│ indent-output │ i     │ indent output visually                                          │
│ no-output     │ O     │ execute code without outputting results                         │
│ no-run        │ N     │ do not execute code in block                                    │
│ try           │ t     │ execute block inside `try {}` for error handling                │
│ new-instance  │ n     │ execute block in new Nushell instance (useful with `try` block) │
╰─────long──────┴─short─┴───────────────────────────description───────────────────────────╯

Stats of changes

By default, numd provides basic stats on changes made.

> let path = [z_examples 1_simple_markdown simple_markdown_with_no_output.md] | path join
> numd run --no-save $path
╭──────────────────┬───────────────────────────────────╮
│ filename         │ simple_markdown_with_no_output.md │
│ nushell_blocks   │ 3                                 │
│ levenshtein_dist │ 38                                │
│ diff_lines       │ +9 (37.5%)                        │
│ diff_words       │ +6 (10.7%)                        │
│ diff_chars       │ +38 (11%)                         │
╰──────────────────┴───────────────────────────────────╯

Styling outputs

It is possible to set Nushell visual settings (and all the others) using the --prepend-itermid option. Just pass a code there to be prepended into our intermed-script.nu and executed before all parts of the code.

let path = $nu.temp-path | path join simple_nu_table.md

# let's generate some markdown and save it to the `simple_nu_table.md` file in the temp directory
"```nushell\n[[a b c]; [1 2 3]]\n```\n" | save -f $path

# let's run this file to see it's outputs
numd run $path --echo --no-save --no-stats --prepend-code "$env.config.footer_mode = 'never'
    $env.config.table.header_on_separator = false
    $env.config.table.index_mode = 'never'
    $env.config.table.mode = 'basic_compact'"

Output:

//  ```nushell
//  [[a b c]; [1 2 3]]
//  ```
//
//  Output:
//
//  ```
//  +---+---+---+
//  | a | b | c |
//  | 1 | 2 | 3 |
//  +---+---+---+
//  ```

numd clear-outputs

> numd clear-outputs --help | numd parse-help
// Description:
//   Remove numd execution outputs from the file
//
//
// Usage:
//   > clear-outputs {flags} <file>
//
//
// Flags:
//   -o, --result-md-path <path>: path to a resulting `.md` file; if omitted, updates the original file
//   --echo: output resulting markdown to the terminal instead of writing to file
//   --strip-markdown: keep only Nushell script, strip all markdown tags
//
//
// Parameters:
//   file <path>: path to a `.md` file containing numd output to be cleared
//
//
// Input/output types:
//   ╭─#─┬──input──┬─output──╮
//   │ 0 │ nothing │ string  │
//   │ 1 │ nothing │ nothing │
//   ╰─#─┴──input──┴─output──╯

numd capture

numd can use the display_output hook to write the current session prompts together with their output into a specified markdown file. There are corresponding commands numd capture start and numd capture stop.

> numd capture start --help | numd parse-help
// Description:
//   start capturing commands and their outputs into a file
//
//
// Usage:
//   > start {flags} (file)
//
//
// Flags:
//   --separate: don't use `>` notation, create separate blocks for each pipeline
//
//
// Parameters:
//   file <path>:  (optional, default: 'numd_capture.md')
//
//
// Input/output types:
//   ╭─#─┬──input──┬─output──╮
//   │ 0 │ nothing │ nothing │
//   ╰─#─┴──input──┴─output──╯

> numd capture stop --help | numd parse-help
// Description:
//   stop capturing commands and their outputs
//
//
// Usage:
//   > stop
//
//
// Input/output types:
//   ╭─#─┬──input──┬─output──╮
//   │ 0 │ nothing │ nothing │
//   ╰─#─┴──input──┴─output──╯

Some random familiar examples

> ls z_examples | sort-by name | reject modified size
╭──────────────────name───────────────────┬─type─╮
│ z_examples/1_simple_markdown            │ dir  │
│ z_examples/2_numd_commands_explanations │ dir  │
│ z_examples/3_book_types_of_data         │ dir  │
│ z_examples/4_book_working_with_lists    │ dir  │
│ z_examples/5_simple_nu_table            │ dir  │
│ z_examples/6_edge_cases                 │ dir  │
│ z_examples/7_image_output               │ dir  │
│ z_examples/999_numd_internals           │ dir  │
│ z_examples/99_strip_markdown            │ dir  │
╰──────────────────name───────────────────┴─type─╯

> sys host | get boot_time
Tue, 29 Oct 2024 18:51:21 -0300 (2 weeks ago)

> 2 + 2
4

> git tag | lines | sort -n | last
0.1.15

Real fight examples to try

# output the result of execution to terminal without updating the file
[z_examples 1_simple_markdown simple_markdown.md]
| path join
| numd run $in --echo --no-save

# run examples in the `types_of_data.md` file,
# save intermed nushell script to `types_of_data.md_intermed.nu`
[z_examples 3_book_types_of_data types_of_data.md]
| path join
| numd run $in --no-backup --intermed-script $'($in)_intermed.nu'

Development and testing

Nushell Markdown documents used together with Git could often serve as a convenient way to test custom and built-in Nushell commands.

Testing of the numd module itself is done via the testing command in tools.nu in the root repository folder: whatever changes are made in the module - it could be easily seen if they break anything (both by the Levenshtein distance metric or by git diff of the updated example files versus their initial versions) . Please, feel free to try it on your own.

> nu tools.nu testing
╭───────────filename────────────┬─nushell_blocks─┬─levenshtein_dist─┬─diff_lines─┬─diff_words─┬─diff_chars─╮
│ types_of_data.md              │             31 │                0 │ 0%         │ 0%         │ 0%         │
│ simple_markdown.md            │              3 │                0 │ 0%         │ 0%         │ 0%         │
│ numd_commands_explanations.md │              7 │                0 │ 0%         │ 0%         │ 0%         │
│ working_with_lists.md         │             18 │                0 │ 0%         │ 0%         │ 0%         │
│ README.md                     │             10 │                0 │ 0%         │ 0%         │ 0%         │
╰───────────filename────────────┴─nushell_blocks─┴─levenshtein_dist─┴─diff_lines─┴─diff_words─┴─diff_chars─╯