fix(cli/emit): Check JS roots with // @ts-check (denoland#14090)

cli/emit.rs

@@ -279,12 +279,21 @@ fn get_tsc_roots(
  .entries()
  .into_iter()
  .filter_map(|(specifier, module_entry)| match module_entry {
- ModuleEntry::Module { media_type, .. } => match &media_type {
+ ModuleEntry::Module {
+ media_type,
+ ts_check,
+ ..
+ } => match &media_type {
  MediaType::TypeScript
  | MediaType::Tsx
  | MediaType::Mts
  | MediaType::Cts
  | MediaType::Jsx => Some((specifier.clone(), *media_type)),
+ MediaType::JavaScript | MediaType::Mjs | MediaType::Cjs
+ if check_js || *ts_check =>
+ {
+ Some((specifier.clone(), *media_type))
+ }
  _ => None,
  },
  _ => None,
@@ -461,20 +470,25 @@ pub fn check_and_maybe_emit(
  // resolve it via the graph.
  let graph_data = graph_data.read();
  let specifier = graph_data.follow_redirect(&specifiers[0]);
- let (source_bytes, media_type) = match graph_data.get(&specifier) {
- Some(ModuleEntry::Module {
- code, media_type, ..
- }) => (code.as_bytes(), *media_type),
- _ => {
- log::debug!("skipping emit for {}", specifier);
- continue;
- }
- };
+ let (source_bytes, media_type, ts_check) =
+ match graph_data.get(&specifier) {
+ Some(ModuleEntry::Module {
+ code,
+ media_type,
+ ts_check,
+ ..
+ }) => (code.as_bytes(), *media_type, *ts_check),
+ _ => {
+ log::debug!("skipping emit for {}", specifier);
+ continue;
+ }
+ };
  // Sometimes if `tsc` sees a CommonJS file or a JSON module, it will
  // _helpfully_ output it, which we don't really want to do unless
  // someone has enabled check_js.
  if matches!(media_type, MediaType::Json)
  || (!check_js
+ && !ts_check
  && matches!(
  media_type,
  MediaType::JavaScript | MediaType::Cjs | MediaType::Mjs
@@ -862,10 +876,13 @@ fn valid_emit(
  reload_exclusions: &HashSet<ModuleSpecifier>,
 ) -> bool {
  let config_bytes = ts_config.as_bytes();
- let emit_js = ts_config.get_check_js();
+ let check_js = ts_config.get_check_js();
  for (specifier, module_entry) in graph_data.entries() {
  if let ModuleEntry::Module {
- code, media_type, ..
+ code,
+ media_type,
+ ts_check,
+ ..
  } = module_entry
  {
  match media_type {
@@ -875,7 +892,7 @@ fn valid_emit(
  | MediaType::Tsx
  | MediaType::Jsx => {}
  MediaType::JavaScript | MediaType::Mjs | MediaType::Cjs => {
- if !emit_js {
+ if !check_js && !ts_check {
  continue;
  }
  }

cli/graph_util.rs

@@ -13,12 +13,18 @@ use deno_graph::ModuleGraphError;
 use deno_graph::ModuleKind;
 use deno_graph::Range;
 use deno_graph::Resolved;
+use once_cell::sync::Lazy;
+use regex::Regex;
 use std::collections::BTreeMap;
 use std::collections::HashMap;
 use std::collections::HashSet;
 use std::collections::VecDeque;
 use std::sync::Arc;
 
+/// Matches the `@ts-check` pragma.
+static TS_CHECK_RE: Lazy<Regex> =
+ Lazy::new(|| Regex::new(r#"(?i)^\s*@ts-check(?:\s+|$)"#).unwrap());
+
 pub fn contains_specifier(
  v: &[(ModuleSpecifier, ModuleKind)],
  specifier: &ModuleSpecifier,
@@ -33,6 +39,8 @@ pub enum ModuleEntry {
  code: Arc<String>,
  dependencies: BTreeMap<String, Dependency>,
  media_type: MediaType,
+ /// Whether or not this is a JS/JSX module with a `@ts-check` directive.
+ ts_check: bool,
  /// A set of type libs that the module has passed a type check with this
  /// session. This would consist of window, worker or both.
  checked_libs: HashSet<TypeLib>,
@@ -122,9 +130,23 @@ impl GraphData {
  }
  }
  }
+ let ts_check = match &media_type {
+ MediaType::JavaScript
+ | MediaType::Mjs
+ | MediaType::Cjs
+ | MediaType::Jsx => {
+ let parsed_source = module.maybe_parsed_source.as_ref().unwrap();
+ parsed_source
+ .get_leading_comments()
+ .iter()
+ .any(|c| TS_CHECK_RE.is_match(&c.text))
+ }
+ _ => false,
+ };
  let module_entry = ModuleEntry::Module {
  code,
  dependencies: module.dependencies.clone(),
+ ts_check,
  media_type,
  checked_libs: Default::default(),
  maybe_types,

cli/tests/integration/run_tests.rs

@@ -2726,3 +2726,10 @@ itest!(complex_error {
  output: "complex_error.ts.out",
  exit_code: 1,
 });
+
+// Regression test for https://github.com/denoland/deno/issues/12143.
+itest!(js_root_with_ts_check {
+ args: "run --quiet js_root_with_ts_check.js",
+ output: "js_root_with_ts_check.js.out",
+ exit_code: 1,
+});

cli/tests/testdata/js_root_with_ts_check.js

@@ -0,0 +1,5 @@
+// @ts-check
+
+/** @type {number} */
+const a = "";
+console.log(a);

cli/tests/testdata/js_root_with_ts_check.js.out

@@ -0,0 +1,4 @@
+error: TS2322 [ERROR]: Type 'string' is not assignable to type 'number'.
+const a = "";
+ ^
+ at [WILDCARD]