The new beta follows TypeScript, v4.3, which was released in May. The final v4.4 release is targeted for Aug. 24, according to the iteration plan.
Performance improvements are many, including:
- Faster Path Normalization: This concerns several types of "normalization" on file paths to get them into a consistent format for the compiler to use. Now, paths first undergo quick checks to see whether normalization is even needed, which can help reduce project load time by 5-10 percent on bigger projects, and significantly more in massive projects, according to internal testing.
- Faster Path Mapping: v4.4 now caches the way it constructs path-mappings, resulting in significantly reduced mapping time for projects with several hundred mappings.
- Faster Incremental Builds with
--strict: This fixes what was effectively a bug: redoing type-checking work under
--incremental compilations if
--strict was on, which led to many builds being just as slow as if
--incremental was turned off.
- Faster Source Map Generation for Big Outputs: An optimization for source map generation on extremely large output files has been added. This results in about an 8 percent reduction in emit time when building an older version of the TypeScript compiler.
--force Builds: Now
--force builds avoid unnecessary steps (up-to-date checks to see which files need to be rebuilt) taken when using
--build mode on project references, because when performing a
--force build that information is irrelevant as all project dependencies will be rebuilt from scratch.
// @ts-check or in a project with
checkJs turned off.)
"These spelling suggestions can provide a subtle clue that your code is wrong. We managed to find a few bugs in existing code while testing this feature!"
Other highlights of the beta release as presented by Rosenwasser include:
David Ramel is an editor and writer for Converge360.