feat(unstable): ability to resolve specifiers with no extension, spec…

…ifiers for a directory, and TS files from JS extensions (denoland#21464)

Adds an `--unstable-sloppy-imports` flag which supports the
following for `file:` specifiers:

* Allows writing `./mod` in a specifier to do extension probing.
- ex. `import { Example } from "./example"` instead of `import { Example
} from "./example.ts"`
* Allows writing `./routes` to do directory extension probing for files
like `./routes/index.ts`
* Allows writing `./mod.js` for *mod.ts* files.

This functionality is **NOT RECOMMENDED** for general use with Deno:

1. It's not as optimal for perf:
https://marvinh.dev/blog/speeding-up-javascript-ecosystem-part-2/
1. It makes tooling in the ecosystem more complex in order to have to
understand this.
1. The "Deno way" is to be explicit about what you're doing. It's better
in the long run.
1. It doesn't work if published to the Deno registry because doing stuff
like extension probing with remote specifiers would be incredibly slow.

This is instead only recommended to help with migrating existing
projects to Deno. For example, it's very useful for getting CJS projects
written with import/export declaration working in Deno without modifying
module specifiers and for supporting TS ESM projects written with
`./mod.js` specifiers.

This feature will output warnings to guide the user towards correcting
their specifiers. Additionally, quick fixes are provided in the LSP to
update these specifiers:

cli/Cargo.toml

@@ -60,16 +60,16 @@ deno_ast = { workspace = true, features = ["bundler", "cjs", "codegen", "dep_gra
 deno_cache_dir = "=0.6.1"
 deno_config = "=0.6.5"
 deno_core = { workspace = true, features = ["include_js_files_for_snapshotting"] }
-deno_doc = { version = "=0.73.5", features = ["html"] }
-deno_emit = "=0.31.5"
-deno_graph = "=0.61.5"
+deno_doc = { version = "=0.74.0", features = ["html"] }
+deno_emit = "=0.32.0"
+deno_graph = "=0.62.0"
 deno_lint = { version = "=0.52.2", features = ["docs"] }
 deno_lockfile.workspace = true
 deno_npm = "0.15.3"
 deno_runtime = { workspace = true, features = ["dont_create_runtime_snapshot", "include_js_files_for_snapshotting"] }
 deno_semver = "0.5.1"
 deno_task_shell = "=0.14.0"
-eszip = "=0.55.5"
+eszip = "=0.56.0"
 napi_sym.workspace = true
 
 async-trait.workspace = true

cli/args/flags.rs

@@ -455,6 +455,7 @@ pub struct Flags {
  pub unstable: bool,
  pub unstable_bare_node_builtins: bool,
  pub unstable_byonm: bool,
+ pub unstable_sloppy_imports: bool,
  pub unstable_workspaces: bool,
  pub unstable_features: Vec<String>,
  pub unsafely_ignore_certificate_errors: Option<Vec<String>>,
@@ -862,6 +863,7 @@ pub fn flags_from_vec(args: Vec<String>) -> clap::error::Result<Flags> {
  flags.unstable_bare_node_builtins =
  matches.get_flag("unstable-bare-node-builtins");
  flags.unstable_byonm = matches.get_flag("unstable-byonm");
+ flags.unstable_sloppy_imports = matches.get_flag("unstable-sloppy-imports");
  flags.unstable_workspaces = matches.get_flag("unstable-workspaces");
 
  if matches.get_flag("quiet") {
@@ -981,6 +983,17 @@ fn clap_root() -> Command {
  .action(ArgAction::SetTrue)
  .global(true),
  )
+ .arg(
+ Arg::new("unstable-sloppy-imports")
+ .long("unstable-sloppy-imports")
+ .help(
+ "Enable unstable resolving of specifiers by extension probing, .js to .ts, and directory probing.",
+ )
+ .env("DENO_UNSTABLE_SLOPPY_IMPORTS")
+ .value_parser(FalseyValueParser::new())
+ .action(ArgAction::SetTrue)
+ .global(true),
+ )
  .arg(
  Arg::new("unstable-workspaces")
  .long("unstable-workspaces")

cli/args/mod.rs

@@ -1342,7 +1342,7 @@ impl CliOptions {
  || self
  .maybe_config_file()
  .as_ref()
- .map(|c| c.json.unstable.contains(&"bare-node-builtins".to_string()))
+ .map(|c| c.has_unstable("bare-node-builtins"))
  .unwrap_or(false)
  }
 
@@ -1355,7 +1355,16 @@ impl CliOptions {
  || self
  .maybe_config_file()
  .as_ref()
- .map(|c| c.json.unstable.iter().any(|c| c == "byonm"))
+ .map(|c| c.has_unstable("byonm"))
+ .unwrap_or(false)
+ }
+
+ pub fn unstable_sloppy_imports(&self) -> bool {
+ self.flags.unstable_sloppy_imports
+ || self
+ .maybe_config_file()
+ .as_ref()
+ .map(|c| c.has_unstable("sloppy-imports"))
  .unwrap_or(false)
  }
 

cli/factory.rs

@@ -39,6 +39,7 @@ use crate::npm::CliNpmResolverManagedPackageJsonInstallerOption;
 use crate::npm::CliNpmResolverManagedSnapshotOption;
 use crate::resolver::CliGraphResolver;
 use crate::resolver::CliGraphResolverOptions;
+use crate::resolver::UnstableSloppyImportsResolver;
 use crate::standalone::DenoCompileBinaryWriter;
 use crate::tools::check::TypeChecker;
 use crate::util::file_watcher::WatcherCommunicator;
@@ -381,6 +382,11 @@ impl CliFactory {
  Ok(Arc::new(CliGraphResolver::new(CliGraphResolverOptions {
  fs: self.fs().clone(),
  cjs_resolutions: Some(self.cjs_resolutions().clone()),
+ sloppy_imports_resolver: if self.options.unstable_sloppy_imports() {
+ Some(UnstableSloppyImportsResolver::new(self.fs().clone()))
+ } else {
+ None
+ },
  node_resolver: Some(self.node_resolver().await?.clone()),
  npm_resolver: if self.options.no_npm() {
  None

cli/graph_util.rs

@@ -857,7 +857,7 @@ mod test {
  use deno_graph::ResolutionError;
  use deno_graph::SpecifierError;
 
- use crate::graph_util::get_resolution_error_bare_node_specifier;
+ use super::*;
 
  #[test]
  fn import_map_node_resolution_error() {

cli/lsp/diagnostics.rs

@@ -1097,7 +1097,10 @@ impl DenoDiagnostic {
  changes: Some(HashMap::from([(
  specifier.clone(),
  vec![lsp::TextEdit {
- new_text: format!("\"{}\"", data.redirect),
+ new_text: format!(
+ "\"{}\"",
+ specifier_text_for_redirected(&data.redirect, specifier)
+ ),
  range: diagnostic.range,
  }],
  )])),
@@ -1193,6 +1196,27 @@ impl DenoDiagnostic {
  }
 }
 
+fn specifier_text_for_redirected(
+ redirect: &lsp::Url,
+ referrer: &lsp::Url,
+) -> String {
+ if redirect.scheme() == "file" && referrer.scheme() == "file" {
+ // use a relative specifier when it's going to a file url
+ match referrer.make_relative(redirect) {
+ Some(relative) => {
+ if relative.starts_with('.') {
+ relative
+ } else {
+ format!("./{}", relative)
+ }
+ }
+ None => redirect.to_string(),
+ }
+ } else {
+ redirect.to_string()
+ }
+}
+
 fn diagnose_resolution(
  snapshot: &language_server::StateSnapshot,
  dependency_key: &str,
@@ -1833,4 +1857,29 @@ let c: number = "a";
  ])
  );
  }
+
+ #[test]
+ fn test_specifier_text_for_redirected() {
+ #[track_caller]
+ fn run_test(specifier: &str, referrer: &str, expected: &str) {
+ let result = specifier_text_for_redirected(
+ &ModuleSpecifier::parse(specifier).unwrap(),
+ &ModuleSpecifier::parse(referrer).unwrap(),
+ );
+ assert_eq!(result, expected);
+ }
+
+ run_test("file:https:///a/a.ts", "file:https:///a/mod.ts", "./a.ts");
+ run_test("file:https:///a/a.ts", "file:https:///a/sub_dir/mod.ts", "../a.ts");
+ run_test(
+ "file:https:///a/sub_dir/a.ts",
+ "file:https:///a/mod.ts",
+ "./sub_dir/a.ts",
+ );
+ run_test(
+ "https://deno.land/x/example/mod.ts",
+ "file:https:///a/sub_dir/a.ts",
+ "https://deno.land/x/example/mod.ts",
+ );
+ }
 }