chore: add regex globals

[arendjr]

Summary

Introduces global type definitions for the regex type.

This is a stepping stone towards resolving #8034.

Note that the regex types don't carry flags yet, which I think still needs to be done to resolve the issue.

Please be aware there are two regex types in our type inference engine: there are instances of the RegExp class (created when using new RegExp()), but there are also regex literals (/ab+c/).

Test Plan

Test added. Snapshots updated.

Docs

N/A

[changeset-bot]

⚠️ No Changeset found

Latest commit: 58d3249

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[coderabbitai]

Walkthrough

This pull request enhances RegExp type inference in Biome's JavaScript type system. Changes include reworking literal value formatting to include explicit type prefixes (e.g., "string:", "number:"), adding three new RegExp-related type IDs to the global type registry, extending the global resolver with RegExp class and method definitions, introducing a helper method to detect RegExp type references, and adding a corresponding test for regex literal type inference.

Suggested labels

L-JavaScript, A-Type-Inference

Suggested reviewers

• ematipico

Pre-merge checks and finishing touches

✅ Passed checks (3 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title 'chore: add regex globals' directly describes the main change—introducing global type definitions for regex types.
Description check	✅ Passed	The description clearly relates to the changeset, explaining the purpose of adding global regex type definitions and their role as a stepping stone for issue #8034.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

✨ Finishing touches

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🧪 Generate unit tests (beta)

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• Post copyable unit tests in a comment

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📜 Recent review details

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📥 Commits

Reviewing files that changed from the base of the PR and between bf1a836 and 58d3249.

⛔ Files ignored due to path filters (30)

• crates/biome_js_type_info/tests/snapshots/infer_flattened_type_from_direct_promise_instance.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/infer_flattened_type_from_static_promise_function.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/infer_flattened_type_of_typeof_expression.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/infer_resolved_type_from_direct_promise_instance.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/infer_resolved_type_from_static_promise_function.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/infer_type_of_binary_expression_eq.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/infer_type_of_binary_expression_ne.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/infer_type_of_literal.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/infer_type_of_regex.snap is excluded by !**/*.snap and included by **
• crates/biome_js_type_info/tests/snapshots/test_reference_to_falsy_subset_of.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_export_type_referencing_imported_type.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_export_types.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_exports.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_generic_mapped_value.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_generic_return_value.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_generic_return_value_with_multiple_modules.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_import_as_namespace.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_merged_types.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_multiple_reexports.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_promise_export.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_promise_from_imported_function_returning_imported_promise_type.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_promise_from_imported_function_returning_reexported_promise_type.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_recursive_looking_vfile.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_single_reexport.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_type_of_property_with_getter.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_type_of_this_in_class_assign.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_type_of_this_in_class_export.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_type_of_this_in_class_plain.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_type_of_this_in_class_wrong_scope.snap is excluded by !**/*.snap and included by **
• crates/biome_module_graph/tests/snapshots/test_resolve_type_of_this_in_object.snap is excluded by !**/*.snap and included by **

📒 Files selected for processing (4)

• crates/biome_js_type_info/src/format_type_info.rs (1 hunks)
• crates/biome_js_type_info/src/globals.rs (7 hunks)
• crates/biome_js_type_info/src/type_data.rs (1 hunks)
• crates/biome_js_type_info/tests/local_inference.rs (1 hunks)

🧰 Additional context used

🧠 Learnings (2)

📚 Learning: 2025-08-20T16:24:59.781Z

Learnt from: arendjr
Repo: biomejs/biome PR: 7266
File: crates/biome_js_type_info/src/type.rs:94-102
Timestamp: 2025-08-20T16:24:59.781Z
Learning: In crates/biome_js_type_info/src/type.rs, the flattened_union_variants() method returns TypeReference instances that already have the correct module IDs applied to them. These references should be used directly with resolver.resolve_reference() without applying additional module ID transformations, as variant references may originate from nested unions in different modules.

Applied to files:

• crates/biome_js_type_info/src/type_data.rs
• crates/biome_js_type_info/src/globals.rs

📚 Learning: 2025-09-09T18:10:05.095Z

Learnt from: arendjr
Repo: biomejs/biome PR: 6710
File: crates/biome_js_type_info/src/helpers.rs:102-124
Timestamp: 2025-09-09T18:10:05.095Z
Learning: Global constants like GLOBAL_ARRAY_ID are stored by the global resolver and should never have module IDs applied to them. Module IDs only apply to module resolvers, not global resolvers. When working with global type constants, use them directly without module ID transformations.

Applied to files:

• crates/biome_js_type_info/src/globals.rs

🧬 Code graph analysis (3)

crates/biome_js_type_info/src/format_type_info.rs (3)

crates/biome_formatter/src/lib.rs (2)

• write (1428-1435)
• as_str (169-185)

crates/biome_formatter/src/builders.rs (3)

• token (251-259)
• space (606-608)
• text (279-283)

crates/biome_js_type_info/src/type_data/literal.rs (4)

• text (44-46)
• as_bool (11-13)
• as_str (39-41)
• as_str (89-91)

crates/biome_js_type_info/tests/local_inference.rs (2)

crates/biome_js_type_info/tests/utils.rs (2)

• get_expression (224-238)
• assert_type_data_snapshot (22-55)

crates/biome_js_type_info/src/globals.rs (1)

• default (184-410)

crates/biome_js_type_info/src/globals.rs (2)

crates/biome_js_type_info/src/type_data.rs (19)

• new (39-43)
• new (1436-1440)
• new (1471-1481)
• from (174-176)
• from (180-182)
• from (186-188)
• from (192-194)
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• from (234-236)
• from (240-242)
• from (246-248)
• from (721-723)
• from (1020-1025)
• instance_of (295-297)

crates/biome_rowan/src/text.rs (2)

• new_static (182-186)
• new_static (262-271)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (12)

• GitHub Check: Test (depot-ubuntu-24.04-arm-16)
• GitHub Check: Test (depot-windows-2022-16)
• GitHub Check: Lint project (depot-ubuntu-24.04-arm-16)
• GitHub Check: Check Dependencies
• GitHub Check: Lint project (depot-windows-2022)
• GitHub Check: Documentation
• GitHub Check: End-to-end tests
• GitHub Check: Test Node.js API
• GitHub Check: Bench (biome_js_analyze)
• GitHub Check: Bench (biome_js_parser)
• GitHub Check: Bench (biome_js_formatter)
• GitHub Check: autofix

🔇 Additional comments (7)

crates/biome_js_type_info/src/format_type_info.rs (1)

789-837: LGTM! Consistent type-prefixed formatting for literals.

The rework to emit explicit type prefixes ("bigint:", "bool:", "number:", "regex:", "string:") for each Literal variant improves clarity in formatted output and snapshots. The pattern is applied uniformly across all variants.

crates/biome_js_type_info/tests/local_inference.rs (1)

37-46: LGTM! Well-structured test for regex type inference.

The new test follows established patterns in the file and validates type inference for regex literals, exercising the newly introduced RegExp global types.

crates/biome_js_type_info/src/type_data.rs (1)

1405-1414: LGTM! Consistent helper method for RegExp detection.

The new is_regex() method mirrors the existing is_array() and is_promise() patterns, maintaining consistency in the API. Documentation appropriately notes this is a semantic check after resolution, not a substitute for it.

crates/biome_js_type_info/src/globals.rs (4)

62-80: LGTM! RegExp type IDs properly integrated.

Three new predefined type IDs added (INSTANCEOF_REGEXP_ID, REGEXP_ID, REGEXP_EXEC_ID), with all subsequent IDs correctly shifted and NUM_PREDEFINED_TYPES updated from 41 to 44. The arithmetic is sound.

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89-91: LGTM! Global constants and type names properly extended.

The new global RegExp constants and type name mappings are consistent with existing patterns. All indices in global_type_name() correctly updated to reflect the new type ID positions.

Also applies to: 149-169

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227-235: LGTM! RegExp class and method definitions properly structured.

The regexp_method_definition helper mirrors the Promise pattern, and the RegExp class definition is appropriately constructed with an exec method. Correctly uses no type parameters, as RegExp is not generic.

Also applies to: 333-341

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485-486: LGTM! RegExp qualifier resolution properly integrated.

The new condition in resolve_qualifier() follows the established pattern for Array and Promise, returning GLOBAL_REGEXP_ID for RegExp references without type parameters. Correctly placed in the resolution chain.

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[Netail]

Note that the regex types don't carry flags yet, which I think still needs to be done to resolve the issue.

Correct :)

[codspeed-hq]

CodSpeed Performance Report

Merging #8166 will not alter performance

_{Comparing arendjr:add-regex-globals (58d3249) with main (bf1a836)¹}

Summary

✅ 58 untouched
⏩ 95 skipped²

Footnotes

1. No successful run was found on main (12d5b42) during the generation of this report, so bf1a836 was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩

2. 95 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩