Enabled required features from examples automatically

docs/src/SUMMARY.md

@@ -13,6 +13,7 @@
   - [`getrandom`](cli/web/getrandom.md)
   - [Default `index.html`](cli/web/default-index-html.md)
 - [Linter](cli/linter.md)
+- [Running Examples](cli/examples.md)
 - [Configuration](cli/configuration.md)
   - [Configuration Reference](cli/configuration/reference.md)
 - [Troubleshooting](cli/troubleshooting.md)

docs/src/cli/examples.md

@@ -0,0 +1,24 @@
+# Examples
+
+The CLI makes it easy to build, run and lint examples by automatically enabling required features of the example.
+
+## Build and run a specific example
+
+```sh
+# Run the `web_asset` example from https://github.com/bevyengine/bevy that requires the feature `https`.
+bevy run --example web_asset
+info: enabling required_features: ["https"], for example: web_asset
+
+# Build the `web_asset` example in the web.
+bevy build --example web_asset web
+info: enabling required_features: ["https"], for example: web_asset
+```
+
+## Build all examples
+
+The CLI supports building all examples only for the native target, for the web this is not supported yet.
+When building all examples, the CLI will build with `--all-features`.
+
+```sh
+bevy build --examples
+```

docs/src/cli/index.md

@@ -5,6 +5,7 @@ The CLI is a prototype tool intended to streamline common tasks when working on
 - [**Project Scaffolding**](scaffolding.md)
 - [**Build and running Bevy Web Apps**](web.md)
 - [**Linter Integration**](linter.md)
+- [**Enabling required features for examples**](examples.md)
 
 [initial scope document]: https://hackmd.io/cCHAfbtaSviU_MDnbNHKxg
 [original issue]: https://github.com/bevyengine/bevy/issues/436

src/commands/build/mod.rs

@@ -1,6 +1,8 @@
 //! Provides functionalities to build a Bevy app targeting either native or web platforms.
 
 pub use args::*;
+use cargo_metadata::TargetKind;
+use tracing::info;
 
 #[cfg(feature = "web")]
 use crate::web::build::build_web;
@@ -39,6 +41,39 @@ pub fn build(args: &mut BuildArgs) -> anyhow::Result<()> {
 
     args.apply_config(&config);
 
+    // If a specific example was passed, extend the already present features with the
+    // required_features from this example.
+    if let Some(example) = &args.cargo_args.target_args.example
+    // Search in the current workspace packages for an `example` target that matches the given
+    // example name.
+        && let Some(example_target) = metadata
+            .workspace_packages()
+            .iter()
+            .flat_map(|p| p.targets.clone())
+            .find(|t| t.name.as_str() == example && t.kind.contains(&TargetKind::Example))
+    {
+        let required_features = example_target.required_features;
+
+        info!(
+            "enabling required_features: {:?}, for example: {example}",
+            required_features
+        );
+
+        args.cargo_args
+            .feature_args
+            .features
+            .extend(required_features);
+    }
+    // build `--examples` with all features enabled.
+    else if args.cargo_args.target_args.is_examples {
+        args.cargo_args
+            .feature_args
+            .features
+            .push("--all-features".to_owned());
+
+        info!("automatically added `--all-features` to build examples with all features enabled");
+    }
+
     #[cfg(feature = "web")]
     if args.is_web() {
         build_web(args, &metadata)?;

src/commands/lint/mod.rs

@@ -1,5 +1,5 @@
 pub use args::*;
-use tracing::error;
+use tracing::{error, info};
 
 #[cfg(feature = "rustup")]
 use crate::commands::lint::install::install_linter;
@@ -145,6 +145,39 @@ fn build_lint_cmd(args: &mut LintArgs) -> anyhow::Result<CommandExt> {
         }
     }
 
+    // If a specific example was passed, extend the already present features with the
+    // required_features from this example.
+    if let Some(example) = &args.cargo_args.target_args.example
+    // Search in the current workspace packages for an `example` target that matches the given
+    // example name.
+        && let Some(example_target) = metadata
+            .workspace_packages()
+            .iter()
+            .flat_map(|p| p.targets.clone())
+            .find(|t| t.name.as_str() == example && t.kind.contains(&cargo_metadata::TargetKind::Example))
+    {
+        let required_features = example_target.required_features;
+
+        info!(
+            "enabling required_features: {:?}, for example: {example}",
+            required_features
+        );
+
+        args.cargo_args
+            .feature_args
+            .features
+            .extend(required_features);
+    }
+    // build `--examples` with all features enabled.
+    else if args.cargo_args.target_args.is_examples {
+        args.cargo_args
+            .feature_args
+            .features
+            .push("--all-features".to_owned());
+
+        info!("automatically added `--all-features` to check examples with all features enabled");
+    }
+
     let cargo_args = args.cargo_args_builder();
 
     cmd.args(cargo_args)

src/commands/run/mod.rs

@@ -1,5 +1,7 @@
 //! Provides functionalities to run a Bevy app targeting either native or web platforms.
 
+use tracing::info;
+
 pub use self::args::*;
 #[cfg(feature = "web")]
 use crate::web::run::run_web;
@@ -37,6 +39,29 @@ pub fn run(args: &mut RunArgs) -> anyhow::Result<()> {
 
     args.apply_config(&config);
 
+    // Extend the already present features with the required_features from this example.
+    if let Some(example) = &args.cargo_args.target_args.example
+    // Search in the current workspace packages for an `example` target that matches the given
+    // example name.
+        && let Some(example_target) = metadata
+            .workspace_packages()
+            .iter()
+            .flat_map(|p| p.targets.clone())
+            .find(|t| t.name.as_str() == example && t.kind.contains(&cargo_metadata::TargetKind::Example))
+    {
+        let required_features = example_target.required_features;
+
+        info!(
+            "enabling required_features: {:?}, for example: {example}",
+            required_features
+        );
+
+        args.cargo_args
+            .feature_args
+            .features
+            .extend(required_features);
+    }
+
     #[cfg(feature = "web")]
     if args.is_web() {
         return run_web(args, &metadata);