path: root/NEWS.md

# Release notes for Subplot

This file summarises the changes between released versions of Subplot and its
associated libraries, especially with regards to changes visible to
the user of the Subplot software.

# Version 0.5.0, released 2022-09-13

* The big, breaking change for this release is that Subplot now
  expects document metadata in a separate YAML file. It was previously
  embedded in the Markdown input file. This allows us to be more
  strict, when parsing the metadata: we only need to support what
  Subplot needs, not the nearly arbitrary YAML Pandoc supports. Later
  on, it will also enable us to support multiple Markdown files as
  input.

* That change also means that we drop support for use of Subplot as a
  Pandoc filter (the `subplot-filter` command and the `subplot filter`
  subcommand). It doesn't make sense unless the metadata is
  embedded in the Markdown.

* We've renamed things so that we consistently call a Markdown fenced
  code block that is marked as a data file, an "embedded file".
  Previously we also used other names, causing unnecessary confusion.

* The new home page URL is updated in all crate metadata. This means
  crates.io will point at the new location after this release is made.

# Version 0.4.3, released 2022-007-29

- Bump the dependency on the `roadmap` crate to a version that depends
  on `clap` version 3 to that it doesn't drag in `structopt`.

# Version 0.4.2, released 2022-007-28

- New feature: Subplot now supports example blocks: embedded files
  that are in the subplot document only as examples, not for use by
  scenarios.

- Subplot error messages are now a little bit more specific as to the
  cause, and what operation failed.

- Subplot now uses the `time` crate instead of the `chrono` crate to
  avoid a potential security issue.

- Terminology change: we now refer to diagrams as diagrams, not
  graphs.

# Version 0.4.1 (subplotlib only), released 2022-04-17

- Fix issue where subplotlib cannot be built out-of-tree

# Version 0.4.0, released 2022-04-16

- The largest change from the previous release is that Rust based
  subplot scenario test suites are now considered supported.
  You can find an example of this in the `examples/seq` project in
  the Subplot source code.

- To achieve this, bindings are now "polyglot" in the sense that they
  are not language specific, though some bindings may only provide
  implementations for particular languages (e.g. the daemon bindings
  currently only support Python)

- Subplot considers Rust 1.48.0 to be its MSRV. This is to enable
  integration into certain distributions and to work with other projects
  whose MSRVs are around that value.

- A number of quality of life improvements around warning delivery,
  template handling, etc. have been made. For the full details, see
  the Git changelog.

# Version 0.3.1, released 2021-11-16

- The primary purpose of this release is to make the `PATH` bug fix
  available via crates.io, to fix use of Subplot in the Sequoia-PGP
  project. There are no breaking changes, so only the patch level of
  the version number is incremented.

- The licence of Subplot has been changed to
  [MIT-0](https://mit-license.org/), to make it as simple as possible
  to use Subplot on other projects, without having to worry about
  license compatibility. Previously, this was technically possible,
  but the Subplot licence situation was complex enough that it caused
  people ask questions.

  The Subplot developers prefer, for Subplot, to maximize adoption and
  though they would favor a copyleft licence otherwise, they're
  willing to compromise this time.

- A bug has been fixed in the Rust `lib/runcmd` function
  implementation to prepend a directory to the `PATH`, in the
  `subplotlib::steplibrary::runcmd::try_to_run_in` function. The bug
  meant that the directories in `PATH` ended up in the wrong order.

# Version 0.3.0, released 2021-10-20

This is still an ALPHA quality release, and includes breaking changes.

## Breaking changes

You definitely need to pay attention to these changes.

- Subplot is moving to libraries and subplots being able to support
  multiple step implementation languages at once. In this release,
  bindings can indicate different functions for each language. Note
  that a binding only needs to support one language. The new binding
  format is:

```yaml
- given: foo
  impl:
    python:
      function: foo
      cleanup: foo_cleanup
    rust:
      function: somelib::foo
      cleanup: somelib::foo_cleanup
```

- The Subplot code generator now uses the `pulldown-cmark` crate for
  parsing Markdown input. The reason for this change is to not have to
  have Pandoc installed in a CI or other environment that only
  generates and runs test programs.

  The document generator still uses Pandoc for this, but it, too, will
  migrate to `pulldown-cmark` so that all parsing is done in the same
  way.

  The parsing crate should support the same Markdown variants as
  Pandoc does, more or less.

  Unfortunately, the YAML document metadata block is less forgiving
  now. The new metadata parser doesn't accept everything Pandoc does,
  and there will be a need to change input documents. The next release
  of Subplot is likely to introduce further changes, and we will
  document the new metadata format then.

- The generated test programs no longer clear the environment
  variables before running scenarios. This is partly to allow Subplot
  to be more easily ported to operating systems other than Debian
  (such as NixOS, but also Windows and macOS), but also because
  clearing the environment variables is not a good way to make sure
  the tests run in a known environment. Subplot now makes it the
  responsibility of the person running the test program to control
  where it is run: what software is installed, what services are
  available, etc.

- Subplot code generation now refuses documents that have no
  scenarios. Document generation still accepts them so that Subplot
  can be used to produce typeset documents and web pages.

## General

The changes in this section should not break any existing Subplot
documents. They affect all uses of Subplot, regardless of step
implementation language and whether Subplot code or document
generation is used.

- After a bug fix, Subplot now handles better the input files being
  elsewhere than the current directory. If the Markdown input file is
  in `foo/bar/yo.md`, the files referred to from the input file are
  looked up relative to `foo/bar` instead of the current working
  directory.

- Subplot now has initial support for logging to make it easier to
  find out what it's doing, when it's doing something surprising. The
  environment variables `SUBPLOT_LOG`, `SUBPLOT_LOG_FILE`, and
  `SUBPLOT_LOG_FORMAT` (`oneline`, `json`, or `pretty`). What Subplot
  logs is still rudimentary but will be improved over time. We'd
  welcome suggestions.

- The Subplot Debian package now builds in the resource into the
  Subplot binary.

- Document titles can now use markup to indicate `literal` text.

- Subplot now automatically handles versions of Pandoc that don't have
  a separate `pandoc-citeproc` binary, and want the `--citeproc`
  option instead.

- Subplot now works with version 1.48.0 of the Rust language and
  toolchain, in order to make it possible for the Sequoia-PGP project
  to use Subplot.

## Python support

- The generated Python test program now supports the `--run-all`
  (`-k`) option to run all scenarios even if one or more fail.

## Rust support

- Subplot now provides the `subplot-build` crate, for using Subplot
  code generation from another project's `build.rs` script.

- We are in the process of elevating Rust into a supported language,
  so that it will be on par with Python. This release does not get
  there, but starts the process.

## Bash support

- We've not made much effort to improve the Bash support (modulo the
  environment cleanup). Compared to Python and Rust it is not a
  well-support language in Subplot. Lars and Daniel do not feel it is
  a target worth spending much of their free time on, but would
  welcome help with that.

# Version 0.2.2, released 2021-08-07

This is release is meant for use by people other than Subplot's own
developers. It is of ALPHA quality, in that what is implemented is
meant to work, but we reserve the right to make backwards incompatible,
breaking changes in future releases.

## General

- When a scenario step matches more than one binding, the error
  message now lists all the matching bindings to make it easier for
  the user to fix the problem. (By Lars Wirzenius)

- The documentation now explains core concepts relevant to Subplot,
  and suggests an initial workflow for a project using Subplot. (By
  Lars Wirzenius)

## Python support

- The `lib/daemon` Subplot library now uses custom Python code instead
  of the netcat tool. This removes a dependency, and also avoids the
  problem of there being at least two more or less incompatible
  versions of netcat in common use. (By Alexander Batischev)

- The `lib/daemon` library now has a way to pass environment variables
  to the daemon. (By Alexander Batischev)

## Bash support

- The documentation now makes it clearer that the `files_get`
  function returns the contents of the embedded file and not a
  filename. (By Richard Maw)

- Some spelling and other language mistakes have been fixed in the
  documentation for Bash support. (By Richard Maw)

- The `dict` helper functions can now read embedded files. (By Richard
  Maw)

- The generated Bash test program now supports the `--env` option to
  let the user pass in environment variables when invoking the test
  program. (By Richard Maw)

- Assertion functions now return an error rather then terminating the
  test program. This lets cleanups run. (By Richard Maw)

# Version 0.2.1, released 2021-07-11

This is the first release meant for use by people other than Subplot's
own developers.

- The locations of the `dot` and `plantuml` programs and for the Java
  byte code interpreter can now be configured when Subplot is invoked,
  which is useful when they're not installed in the locations where
  Debian puts them. Those programs are used by Subplot to render
  diagrams.

- The `./check` script now outputs the last one hundred lines or so of
  the log file produced by the generated test program, if that program
  fails. This makes it easier to debug failures under CI.

- Additionally, there have been some minor tweaks only visible to
  those developing Subplot itself.

# Version 0.2.0, released 2021-06-12

This is the first public release of Subplot. No APIs or other surfaces are to be
considered stable at this time. While the `subplotlib` and `subplotlib-derive`
crates have been published, they do not form part of this release.

The only _template_ which is considered in any sense "supported" in this release
is the `python` template.