Adds deps why functionality

CHANGELOG.md

@@ -8,6 +8,9 @@
   platform for the generated documentation.
   ([Jiangda Wang](https://github.com/frank-iii))
 
+- `gleam deps` now supports `why` operation that takes a package name input, finds it in the deps tree, and then print all the requirements for it from the other packages
+  ([Ramkarthik Krishnamurthy](https://github.com/ramkarthik))
+
 ### Compiler
 
 - The warning for the deprecated `[..]` pattern has been improved.

compiler-cli/src/dependencies.rs

@@ -32,22 +32,16 @@ use crate::{
 };
 
 pub fn list() -> Result<()> {
-    let runtime = tokio::runtime::Runtime::new().expect("Unable to start Tokio async runtime");
-    let project = fs::get_project_root(fs::get_current_directory()?)?;
-    let paths = ProjectPaths::new(project);
-    let config = crate::config::root_config()?;
-    let (_, manifest) = get_manifest(
-        &paths,
-        runtime.handle().clone(),
-        Mode::Dev,
-        &config,
-        &cli::Reporter::new(),
-        UseManifest::Yes,
-    )?;
+    let (_, manifest) = load_manifest()?;
     list_manifest_packages(std::io::stdout(), manifest)
 }
 
-fn list_manifest_packages<W: std::io::Write>(mut buffer: W, manifest: Manifest) -> Result<()> {
+pub fn why(package: String) -> Result<()> {
+    let (_, manifest) = load_manifest()?;
+    list_manifest_package_dependencies(std::io::stdout(), manifest, package)
+}
+
+pub fn list_manifest_packages<W: std::io::Write>(mut buffer: W, manifest: Manifest) -> Result<()> {
     manifest
         .packages
         .into_iter()
@@ -58,6 +52,23 @@ fn list_manifest_packages<W: std::io::Write>(mut buffer: W, manifest: Manifest)
         })
 }
 
+fn list_manifest_package_dependencies<W: std::io::Write>(mut buffer: W, manifest: Manifest, source_package: String) -> Result<()> {
+    manifest
+        .packages
+        .into_iter()
+        .try_for_each(|package| package.requirements.into_iter().try_for_each(|req| {
+            if source_package == req {
+                writeln!(buffer, "{} {}", package.name, package.version)
+            } else {
+                write!(buffer, "")
+            }
+        }))
+        .map_err(|e| Error::StandardIo {
+            action:StandardIoAction::Write,
+            err: Some(e.kind()),
+        })
+}
+
 #[test]
 fn list_manifest_format() {
     let mut buffer = vec![];
@@ -106,6 +117,75 @@ zzz 0.4.0
     )
 }
 
+#[test]
+fn list_manifest_dependencies_format() {
+    let mut buffer = vec![];
+    let source_package = String::from("gleam_stdlib");
+    let manifest = Manifest {
+        requirements: HashMap::new(),
+        packages: vec![
+            ManifestPackage {
+                name: "root".into(),
+                version: Version::parse("1.0.0").unwrap(),
+                build_tools: ["gleam".into()].into(),
+                otp_app: None,
+                requirements: vec![],
+                source: ManifestPackageSource::Hex {
+                    outer_checksum: Base16Checksum(vec![1, 2, 3, 4]),
+                },
+            },
+            ManifestPackage {
+                name: "aaa".into(),
+                version: Version::new(0, 4, 2),
+                build_tools: ["rebar3".into(), "make".into()].into(),
+                otp_app: Some("aaa_app".into()),
+                requirements: vec!["zzz".into(), "gleam_stdlib".into()],
+                source: ManifestPackageSource::Hex {
+                    outer_checksum: Base16Checksum(vec![3, 22]),
+                },
+            },
+            ManifestPackage {
+                name: "zzz".into(),
+                version: Version::new(0, 4, 0),
+                build_tools: ["mix".into()].into(),
+                otp_app: None,
+                requirements: vec![],
+                source: ManifestPackageSource::Hex {
+                    outer_checksum: Base16Checksum(vec![3, 22]),
+                },
+            },
+            ManifestPackage {
+                name: "gleam_erlang".into(),
+                version: Version::new(0, 24, 0),
+                build_tools: ["mix".into()].into(),
+                otp_app: None,
+                requirements: vec!["gleam_stdlib".into()],
+                source: ManifestPackageSource::Hex {
+                    outer_checksum: Base16Checksum(vec![3, 22]),
+                },
+            },
+            ManifestPackage {
+                name: "gleeunit".into(),
+                version: Version::new(1, 0, 2),
+                build_tools: ["mix".into()].into(),
+                otp_app: None,
+                requirements: vec!["gleam_stdlib".into(), "cowlib".into(), "cowboy".into()],
+                source: ManifestPackageSource::Hex {
+                    outer_checksum: Base16Checksum(vec![3, 22]),
+                },
+            },
+        ],
+    };
+    list_manifest_package_dependencies(&mut buffer, manifest, source_package).unwrap();
+    assert_eq!(
+        std::str::from_utf8(&buffer).unwrap(),
+        r#"aaa 0.4.2
+gleam_erlang 0.24.0
+gleeunit 1.0.2
+"#
+    )
+}
+
 #[derive(Debug, Clone, Copy)]
 pub enum UseManifest {
     Yes,
@@ -642,6 +722,21 @@ fn get_manifest<Telem: Telemetry>(
     }
 }
 
+fn load_manifest() -> Result<(bool, Manifest)> {
+    let runtime = tokio::runtime::Runtime::new().expect("Unable to start Tokio async runtime");
+    let project = fs::get_project_root(fs::get_current_directory()?)?;
+    let paths = ProjectPaths::new(project);
+    let config = crate::config::root_config()?;
+    get_manifest(
+        &paths,
+        runtime.handle().clone(),
+        Mode::Dev,
+        &config,
+        &cli::Reporter::new(),
+        UseManifest::Yes,
+    )
+}
+
 fn is_same_requirements(
     requirements1: &HashMap<EcoString, Requirement>,
     requirements2: &HashMap<EcoString, Requirement>,

compiler-cli/src/main.rs

@@ -336,6 +336,13 @@ enum Dependencies {
 
     /// Update dependency packages to their latest versions
     Update,
+
+    /// Find out version requirements
+    Why {
+        /// The name of the package
+        #[arg(required = true)]
+        package: String,
+    },
 }
 
 #[derive(Subcommand, Debug)]
@@ -461,6 +468,8 @@ fn main() {
 
         Command::Deps(Dependencies::Update) => dependencies::update(),
 
+        Command::Deps(Dependencies::Why { package }) => dependencies::why(package),
+
         Command::New(options) => new::create(options, COMPILER_VERSION),
 
         Command::Shell => shell::command(),