feat: MVP for cargo set-version (#482)

The name is not `version` because `cargo version` reports cargo's
version number.

The UI and implementation is lifted from `cargo-release`

Differences with `cargo-release`:
- Relative version changes is behind `--bump` rather than overloading
  the positional argument
  - Motivation: It didn't jive with `set-` in the name
  - Side benefit: Better error reporting

Differences with #414:
- `--bump <level>` vs `--<level>`
  - `--bump` scales better
- This PR supports `--metadata`, `--exclude`

Required future work
- Update workspace dependents when modifying versions

Possible future work
- `--at-least` flag to ignore downgrades, rather than error
- A flag to upgrade everything to the highest requested version (keep
  things in lockstep with `--bump patch`)
- A flag to upgrade min requirements on dependents (rather than just
  updating if semver is broken)
- `--pre` flag so you can do `--bump major --pre alpha` (even `1.0 --pre
  alpha` since I always forget that syntax)

Cargo.toml

@@ -43,6 +43,11 @@ name = "cargo-upgrade"
 path = "src/bin/upgrade/main.rs"
 required-features = ["upgrade"]
 
+[[bin]]
+name = "cargo-set-version"
+path = "src/bin/set-version/main.rs"
+required-features = ["set-version"]
+
 [dependencies]
 atty = { version = "0.2.14", optional = true }
 cargo_metadata = "0.14.0"
@@ -79,10 +84,12 @@ default = [
     "add",
     "rm",
     "upgrade",
+    "set-version",
 ]
 add = ["cli"]
 rm = ["cli"]
 upgrade = ["cli"]
+set-version = ["cli"]
 cli = ["atty", "structopt"]
 test-external-apis = []
 vendored-openssl = ["git2/vendored-openssl"]

README.md

@@ -7,6 +7,7 @@ Currently available subcommands:
 - [`cargo add`](#cargo-add)
 - [`cargo rm`](#cargo-rm)
 - [`cargo upgrade`](#cargo-upgrade)
+- [`cargo set-version`](#cargo-set-version)
 
 [![Build Status](https://github.com/killercup/cargo-edit/workflows/build/badge.svg)](https://github.com/killercup/cargo-edit/actions)
 [![Build Status](https://travis-ci.org/killercup/cargo-edit.svg?branch=master)](https://travis-ci.org/killercup/cargo-edit)
@@ -227,7 +228,7 @@ upgrade to for each can be specified with e.g. `[email protected]` or `serde@>=0.9,<2
 Dev, build, and all target dependencies will also be upgraded. Only dependencies from crates.io are
 supported. Git/path dependencies will be ignored.
 
-All packages in the workspace will be upgraded if the `--workspace` flag is supplied. 
+All packages in the workspace will be upgraded if the `--workspace` flag is supplied.
 The `--workspace` flag may be supplied in the presence of a virtual manifest.
 
 If the '--to-lockfile' flag is supplied, all dependencies will be upgraded to the currently locked
@@ -236,6 +237,54 @@ up-to-date. If the lock file is missing, or it needs to be updated, cargo-upgrad
 error. If the '--to-lockfile' flag is supplied then the network won't be accessed.
 ```
 
+### `cargo set-version`
+
+Set the version in your `Cargo.toml`.
+
+#### Examples
+
+```sh
+# Set the version to the version 1.0.0
+$ cargo set-version 1.0.0
+# Bump the version to the next major
+$ cargo set-version --bump major
+# Bump version to the next minor
+$ cargo set-version --bump minor
+# Bump version to the next patch
+$ cargo set-version --bump patch
+```
+
+#### Usage
+
+```plain
+cargo-set-version 0.7.0
+Change a package's version in the local manifest file (i.e. Cargo.toml)
+
+USAGE:
+    cargo set-version [FLAGS] [OPTIONS] [--] [target]
+
+FLAGS:
+        --all          [deprecated in favor of `--workspace`]
+        --dry-run      Print changes to be made without making them
+    -h, --help         Prints help information
+    -V, --version      Prints version information
+        --workspace    Modify all packages in the workspace
+
+OPTIONS:
+        --bump <bump>             Increment manifest version [possible values: major, minor, patch,
+                                  release, rc, beta, alpha]
+        --exclude <exclude>...    Crates to exclude and not modify
+        --manifest-path <path>    Path to the manifest to upgrade
+    -m, --metadata <metadata>     Specify the version metadata field (e.g. a wrapped libraries version)
+    -p, --package <pkgid>         Package id of the crate to change the version of
+
+ARGS:
+    <target>    Version to change manifests to
+```
+
+For more on `metadata`, see the
+[semver crate's documentation](https://docs.rs/semver/1.0.4/semver/struct.BuildMetadata.html).
+
 ## License
 
 Apache-2.0/MIT

src/bin/set-version/args.rs

@@ -0,0 +1,64 @@
+use std::path::PathBuf;
+
+use structopt::{clap::AppSettings, StructOpt};
+
+#[derive(Debug, StructOpt)]
+#[structopt(bin_name = "cargo")]
+pub(crate) enum Command {
+    /// Change a package's version in the local manifest file (i.e. Cargo.toml).
+    #[structopt(name = "set-version")]
+    Version(Args),
+}
+
+#[derive(Debug, StructOpt)]
+#[structopt(setting = AppSettings::ColoredHelp)]
+#[structopt(group = structopt::clap::ArgGroup::with_name("version").multiple(false))]
+pub(crate) struct Args {
+    /// Version to change manifests to
+    #[structopt(parse(try_from_str), group = "version")]
+    pub(crate) target: Option<semver::Version>,
+
+    /// Increment manifest version
+    #[structopt(long, possible_values(&crate::version::BumpLevel::variants()), group = "version")]
+    pub(crate) bump: Option<crate::version::BumpLevel>,
+
+    /// Specify the version metadata field (e.g. a wrapped libraries version)
+    #[structopt(short = "m", long)]
+    pub metadata: Option<String>,
+
+    /// Path to the manifest to upgrade
+    #[structopt(long = "manifest-path", value_name = "path", conflicts_with = "pkgid")]
+    pub(crate) manifest_path: Option<PathBuf>,
+
+    /// Package id of the crate to change the version of.
+    #[structopt(
+        long = "package",
+        short = "p",
+        value_name = "pkgid",
+        conflicts_with = "path",
+        conflicts_with = "all",
+        conflicts_with = "workspace"
+    )]
+    pub(crate) pkgid: Option<String>,
+
+    /// Modify all packages in the workspace.
+    #[structopt(
+        long = "all",
+        help = "[deprecated in favor of `--workspace`]",
+        conflicts_with = "workspace",
+        conflicts_with = "pkgid"
+    )]
+    pub(crate) all: bool,
+
+    /// Modify all packages in the workspace.
+    #[structopt(long = "workspace", conflicts_with = "all", conflicts_with = "pkgid")]
+    pub(crate) workspace: bool,
+
+    /// Print changes to be made without making them.
+    #[structopt(long = "dry-run")]
+    pub(crate) dry_run: bool,
+
+    /// Crates to exclude and not modify.
+    #[structopt(long)]
+    pub(crate) exclude: Vec<String>,
+}

src/bin/set-version/errors.rs

@@ -0,0 +1,19 @@
+error_chain! {
+    errors {
+        /// We do not support this version requirement at this time
+        UnsupportedVersionReq(req: String) {
+            display("Support for modifying {} is currently unsupported", req)
+        }
+        /// User requested to downgrade a crate
+        VersionDowngreade(current: semver::Version, requested: semver::Version) {
+            display("Cannot downgrade from {} to {}", current, requested)
+        }
+    }
+    links {
+        CargoEditLib(::cargo_edit::Error, ::cargo_edit::ErrorKind);
+    }
+    foreign_links {
+        CargoMetadata(::failure::Compat<::cargo_metadata::Error>);
+        Version(::semver::Error)#[doc = "An error from the semver crate"];
+    }
+}