Make `cargo outdated` part of cargo itself

[behnam]

In Rust ecosystem, one main concern for library developers is to not have semver breaking updates to their package, because of the fear that majority of the dependent packages not getting the routing updates that would follow a breaking update.

There are two general solutions to this problem:

1. The old-school back-porting of updates, so that dependents on any API version would get all the routine updates. This solution can easily become a huge maintenance cost on library developers and is not a common practice in the Rust community at the moment.

2. Help owner of dependent packages to update their dependency versions and apply the changes needed, if any. This solution can be much less time consuming, and distributes the workload throughout the dependency chain. It also means that only the versions being used get the maintenance work needed, but not all theoretically-possible versions. So, in rustacean words: you pay for what you use.

Based on this, I want to propose to add new features to help owners with keeping their dependencies up-to-date. Most of the functionality can be exposed via the cargo update command.

Proposed Features

• Warn on dependencies stuck in older versions. This would be a plain warning on cargo update. The feature would be enabled by default, but there will be an option to disable it; and there can be one release version of Cargo as transition period, where the option is disabled by-default, but there's a notice about the upcoming change, if it applies.

• Commands to auto-update some/all dependency versions to latest. This option would update the relevant manifests to use a latest version of a single or multiple packages. This can also be an option to cargo update, similar to --precise, but instead of updating the lock file, it would also update the manifest with the latest version, or some user-provided version.

  This is a tool to update Cargo Manifest files. Currently, cargo update only works with the Cargo Lock file, so it may be a good idea to have a separate sub-command for the manifest manipulation features. But since it's a core functionality, it's better have this functionality in Cargo proper.

• Auto-update versions to a successful build. This is something that we can aim for in longer term, to have cargo update dependencies, and in case of failures, bisect and find the most-recent version that does not break the builds and/or tests. Best place for this may be a third-party cargo command and not cargo itself.

What do you think?

[behnam]

I'm sure there are many examples where these can be helpful. Here's one that inspired me to write up this proposal: servo/unicode-bidi#46 (comment)

/cc @alexcrichton, @Manishearth, @anowell

[alexcrichton]

I think we'd probably want to canvas what other package managers do here, e.g. do npm, yarn, bundler, rubygems, pip, etc do anything like this? I was personally under the impression that this sort of concerns was typically farmed out to a third-party service.

[behnam]

Here’s a summary of similar features in some other package managers.

---

JS NPM

NPM CLI has built-in outdated subcommand that shows the status of packages that their current, wanted and latest versions do not match.

Like cargo update, the npm update does update the current version to wanted, if needed and possible.

It looks like that npm update does not have any more functionality in this area. Also, no other subcommand look related.

Ref: https://docs.npmjs.com/cli/outdated

Description

(from https://github.com/npm/npm/blob/latest/doc/cli/npm-outdated.md)

This command will check the registry to see if any (or, specific) installed packages are currently outdated.

In the output:

• wanted is the maximum version of the package that satisfies the semver range specified in package.json. If there's no available semver range (i.e. you're running npm outdated --global, or the package isn't included in package.json), then wanted shows the currently-installed version.

• latest is the version of the package tagged as latest in the registry. Running npm publish with no special configuration will publish the package with a dist-tag of latest. This may or may not be the maximum version of the package, or the most-recently published version of the package, depending on how the package's developer manages the latest dist-tag(1).

• location is where in the dependency tree the package is located. Note that npm outdated defaults to a depth of 0, so unless you override that, you'll always be seeing only top-level dependencies that are outdated.

• package type (when using --long / -l) tells you whether this package is a dependency or a devDependency. Packages not included in package.json are always marked dependencies.

Example

Edit package.json and add "underscore": "1.7" to dependencies list.

$ npm outdated
Package     Current  Wanted  Latest  Location
underscore  MISSING   1.7.0   1.8.3  underscore

$ npm install
underscore@1.7.0 node_modules/underscore

$ npm outdated
Package     Current  Wanted  Latest  Location
underscore    1.7.0   1.7.0   1.8.3  underscore

---

JS Yarn

Yarn CLI has built-in outdated subcommand to “checks for outdated package dependencies”.

Ref: https://yarnpkg.com/lang/en/docs/cli/outdated/

Description

Lists version information for all package dependencies. This information includes the currently installed version, the desired version based on semver, and the latest available version.

For example, say your package.json has the following dependencies listed:

"dependencies": {
  "lodash": "4.15.0",
  "underscore": "~1.6.0"
}

The command run should look something like this:

yarn outdated
Package    Current Wanted Latest
lodash     4.15.0  4.15.0 4.16.4
underscore 1.6.0   1.6.0  1.8.3 
✨  Done in 0.72s.

---

Ruby Gems

Gems CLI has built-in outdated subcommand to “display all gems that need updates”.

Ref: http://guides.rubygems.org/command-reference/#gem-outdated

Description

(From ref.)

The outdated command lists gems you may wish to upgrade to a newer version.

You can check for dependency mismatches using the dependency command and update the gems with the update or install commands.

---

Ruby Bundler

Bundler CLI has built-in outdated subcommand to “list installed gems with newer versions available”.

Ref: https://bundler.io/v1.11/bundle_outdated.html

Description

(From ref.)

Outdated lists the names and versions of gems that have a newer version available in the given source. Calling outdated with [GEM [GEM]] will only check for newer versions of the given gems. By default, available prerelease gems will be ignored.

---

Python PIP

PIP CLI's list subcommand has an --outdated option, to "list outdated packages", and an --uptodate option to "list uptodate packages".

Ref: https://pip.pypa.io/en/stable/reference/pip_list/

Examples

List installed packages.

$ pip list
docutils (0.10)
Jinja2 (2.7.2)
MarkupSafe (0.18)
Pygments (1.6)
Sphinx (1.2.1)

List outdated packages (excluding editables), and the latest version available.

$ pip list --outdated
docutils (Current: 0.10 Latest: 0.11)
Sphinx (Current: 1.2.1 Latest: 1.2.2)

[behnam]

In summary:

1. JS and Ruby package managers have built-in outdated subcommand to list packages "not in good standing", in the meaning that their installed version is not what's asked for, or what's asked for is not the latest upstream version (not necessarily the largest one, but the latest marked as stable release).

2. Python PIP has similar functionality via the built-in list subcommand, which makes it more generic, but harder to discover and use for beginner/average users.

3. Looks like all these commands are readonly and have no built-in functionality to update manifest files to the latest version.

4. I have not seen signs of any warning-like functionality regarding out-of-date packages in other commands.

[behnam]

So, IMHO, we can plan to for these functionalities, applicable only to direct dependencies of a package/workspace.

a) A built-in outdated command to help developers find outdated direct dependencies. This would be the readonly and the human-readable output will be similar to the JS/Ruby package managers.

b) Expand (a) to support workspaces.

c) Add options to outdated to make it read-write, updating version numbers of one/more/all outdated dependencies. This, I assume, would be the only/first cargo command to write to the manifest, so would need more design and implementation work.

d) Expand (c) to also support workspaces.

These two can be enough for shell scripts and third-party cargo commands to easily build automations for stable upgrades, meaning that run the tests with single upgrades and revert if there's compile or test errors.

What do you think?

[steveklabnik]

https://crates.io/crates/cargo-outdated works well today

[behnam]

Unfortunately, cargo-outdated package doesn't have any support for workspaces, yet.

Also, a question would be about the original proposal to add optional warning (possibly as an opt-in, via env-var and/or cli option) for cargo update about existence of outdated package(s). I'd like to know how everyone feels about that.

[alexcrichton]

I'd be totally down for adding native outdated support in Cargo itself, but we'd probably want to work closely with the upstream author of cargo-outdated to ensure we coordinate. I know I use it often enough!

[alexcrichton]

Also thanks so much for doing that investigation @behnam, it's quite helpful!

[Keats]

A big +1 for getting cargo outdated built-in.

I've been using cargo-outdated for ages now but as @behnam says, it doesn't support workspaces yet and I use so much with yarn and pip that I believe it should be part of Cargo.

Just to update the yarn output, it actually looks like the following now:

Package            Current       Wanted  Latest  Package Type    URL                                                       
@types/lodash      4.14.70       4.14.71 4.14.71 devDependencies https://www.github.com/DefinitelyTyped/DefinitelyTyped.git
@types/react       15.0.38       15.0.39 15.0.39 devDependencies https://www.github.com/DefinitelyTyped/DefinitelyTyped.git
gulp               4.0.0-alpha.2 exotic  exotic  devDependencies gulpjs/gulp#4.0                                           
signature_pad      2.2.0         2.2.1   2.2.1   dependencies    https://github.com/szimek/signature_pad                   
webpack-dev-server 2.5.1         2.6.1   2.6.1   devDependencies http://github.com/webpack/webpack-dev-server              
Done in 2.27s.

Having the URL in the output is quite nice to be able to see the changes too. Separating the dev-dependencies, build-dependencies and dependencies more cleanly than yarn does would be nice too but then it might become too complex to display with workspaces.

One change to do compared to cargo-outdated that is already mentioned is that imo, it should only list direct dependencies of the project, not subdependencies. Here's an example on one of my projects:

    Name             Project Ver  SemVer Compat  Latest Ver
    hyper               0.10.12        --          0.11.1
    hyper->base64       0.5.2          --          0.6.0
    hyper->mime         0.2.6          --          0.3.2
    hyper->unicase      1.4.2          --          2.0.0
    slug->unidecode     0.2.0          --          0.3.0

I only care about hyper in that list.

If we want to go c) I would recommend checking the yarn upgrade-interactive command as an example of how to handle it.

I'd be interested to do the implementation if that ends up being accepted for cargo!

[behnam]

Good ideas, @Keats!

Having the URL in the output is quite nice to be able to see the changes too.

Agreed.

Also, on a similar note, a --verbose option that shows you also all in good standing, telling you what's been in the check list.

Separating the dev-dependencies, build-dependencies and dependencies more cleanly than yarn does would be nice too

I'm not sure what build-dependencies is here. But, about dev-dependencies, agreed that sometimes it's not a concern and better be able to leave it out of calculation. So, maybe we need a set of options to disable each group of these dependencies.

but then it might become too complex to display with workspaces.

Actually, I think the readonly functionality won't be that complex for workspaces, since there's expected to be one Cargo.lock already.

But, it's a good reminder that we also need something like NPM's location, which shows which local (in the workspace) package is depending on the old version.

And as a plus, this would be Cargo's internal tool to warn on a workspace (or even a package) having direct dependencies on multiple versions of a single package.

it should only list direct dependencies of the project, not subdependencies.

Exactly. I'm not sure if we want a feature to perform these checks more than one level depth. I think we can start with direct deps and see if there's demand for an option to extend.

I'd be interested to do the implementation if that ends up being accepted for cargo!

Awesome! I won't be able to get to this in the next few weeks, but can help with some tests and reviews, if needed.

[behnam]

So, looks like we have general consensus on the core functionality of a built-in outdated subcommand and the rest can be discussed per PR, I assume.

Also, let's CC author of cargo-outdated. @kbknapp, what do you think about these?

[Keats]

I'm not sure what build-dependencies is here. But, about dev-dependencies, agreed that sometimes it's not a concern and better be able to leave it out of calculation. So, maybe we need a set of options to disable each group of these dependencies.

Build dependencies would be bindgen for example: https://github.com/compass-rs/sass-rs/blob/master/sass-sys/Cargo.toml#L16
Dev dependencies is important to display in JS-land since I have more dev dependencies than actual dependencies but I think it still makes sense to display outdated info for all crates listed in my Cargo.toml by default. We could have a flag to disable build/dev dependencies but I don't think it would be used very often: if you run cargo outdated, you usually want to see all of the crates.

Actually, I think the readonly functionality won't be that complex for workspaces, since there's expected to be one Cargo.lock already.

My worry was more on how to display it well in the terminal when you have many workspaces like habitat. I guess scrolling a bit is not a huge issue

[behnam]

Agreed, @Keats. :)

Funny thing about build-dependencies: I could tell what it is, but didn't find it anywhere under the manifest reference: http://doc.crates.io/manifest.html. Turns out, it's only mentioned in this other page: http://doc.crates.io/specifying-dependencies.html#build-dependencies I'll submit a PR to add it to the list in http://doc.crates.io/manifest.html#dependency-sections so it doesn't happen again.