LGTM3 Looks like the tests are at https://wpt.fyi/results/third_party/test262/test/language?label=master&label=experimental&aligned&q=import-defer and still failing because the flag hasn't been flipped yet. If there are test failures after flipping the flag, can you look into getting them to 100%? (Notably, there's one test failing in Safari, will we pass it?)
On Tue, Sep 15, 2026 at 6:16 PM Mike Taylor <[email protected]> wrote: > LGTM2 > On 9/15/26 12:14 p.m., 'Dan Clark' via blink-dev wrote: > > Thank you! LGTM1 > > On Tuesday, September 15, 2026 at 6:14:21 AM UTC-7 Caio Lima wrote: > >> >> >> On Sep 14, 2026, at 6:12 PM, Dan Clark <[email protected]> wrote: >> >> *> Web developers: No signals* >> >> >> I’ve found this documented signal on proposal’s repo >> https://github.com/tc39/proposal-defer-import-eval/issues/18. It’s >> important to notice that since it’s from 2023, it predates the `import >> defer` syntax, but the semantics is the same of current proposal. >> In addition to that, on >> https://2025.stateofjs.com/en-US/features/#js_new_features it’s the >> most popular feature that is not in browsers yet other than decorators, and >> there are some articles and podcasts about it, like >> https://byteiota.com/typescript-59-import-defer-lazy-imports/ (it talks >> mostly about TS import defer) and https://youtu.be/_x5f35JVKt8?t=338. >> >> >> Is there any sign of developer interest we can point to here? >> >> *> Will this feature be supported on all six Blink platforms (Windows, >> Mac, Linux, ChromeOS, Android, and Android WebView)?* >> *> No* >> >> I'd expect this to be shipping everywhere -- should this say "yes"? >> >> >> Sorry, I overlooked this. It’s yes. >> >> >> -- Dan >> On Monday, September 14, 2026 at 9:18:46 AM UTC-7 Caio Lima wrote: >> >>> *Contact emails* >>> [email protected], [email protected] >>> >>> *Explainer* >>> https://github.com/tc39/proposal-defer-import-eval >>> >>> *Specification* >>> https://tc39.es/proposal-defer-import-eval >>> >>> *Summary* >>> `import defer` allows lazily evaluating ES modules, to reduce the >>> startup impact of modules that are not actually needed for the first >>> JavaScript execution. This provides an easier-to-use alternative to dynamic >>> import. While dynamic import provides more benefits, as it allows deferring >>> loading of modules rather than just evaluation, it has a lot of friction >>> due to its asynchronous nature, and thus it's not always usable. The >>> `import defer` TC39 proposal follows the same syntax as `import source`, >>> but it only works with namespace imports: ``` import defer * as namespace >>> from "./some-module.js" ``` The module will be synchronously executed on >>> property access on the module namespace object. To allow synchronous >>> execution, not all of `./some-module.js`'s dependency tree will be >>> deferred. Modules that contain top-level await will be eagerly executed, >>> leaving only the synchronous parts of the tree for later. >>> >>> *Blink component* >>> Blink>JavaScript >>> <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EJavaScript%22> >>> >>> *Web Feature ID* >>> import-defer <https://webstatus.dev/features/import-defer> >>> >>> *Motivation* >>> *No information provided* >>> >>> *Initial public proposal* >>> *No information provided* >>> >>> *TAG review* >>> *No information provided* >>> >>> *TAG review status* >>> Not applicable >>> >>> *Goals for experimentation* >>> None >>> >>> *Risks* >>> >>> >>> *Interoperability and Compatibility* >>> *No information provided* >>> >>> *Gecko*: Positive (https://bugzilla.mozilla.org/show_bug.cgi?id=1952263) >>> Mozilla >>> was originally championing the proposal >>> >>> *WebKit*: Shipped/Shipping ( >>> https://bugs.webkit.org/show_bug.cgi?id=320867) >>> >>> *Web developers*: No signals >>> >>> *Other signals*: >>> >>> *WebView application risks* >>> Does this intent deprecate or change behavior of existing APIs, such >>> that it has potentially high risk for Android WebView-based applications? >>> *No information provided* >>> >>> >>> *Debuggability* >>> >>> Changes were added to CDP to properly support feature UX (for detailed >>> information, see https://issues.chromium.org/issues/552666773) >>> >>> *Will this feature be supported on all six Blink platforms (Windows, >>> Mac, Linux, ChromeOS, Android, and Android WebView)?* >>> No >>> >>> *Is this feature fully tested by web-platform-tests >>> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* >>> Yes >>> Test262 tests: - >>> https://github.com/tc39/test262/tree/main/test/language/import/import-defer >>> - >>> https://github.com/tc39/test262/tree/main/test/language/expressions/dynamic-import/import-defer >>> >>> *Flag name on about://flags* >>> *No information provided* >>> >>> *Finch feature name* >>> V8Flag_js_defer_import_eval >>> >>> *Rollout plan* >>> Will ship enabled for all users >>> >>> *Requires code in //chrome?* >>> False >>> >>> *Tracking bug* >>> https://issues.chromium.org/issues/398218423 >>> >>> *Estimated milestones* >>> Shipping on desktop 155 >>> Shipping on Android 155 >>> Shipping on WebView 155 >>> >>> *Anticipated spec changes* >>> Open questions about a feature may be a source of future web compat or >>> interop issues. Please list open issues (e.g. links to known github issues >>> in the project for the feature specification) whose resolution may >>> introduce web compat/interop risk (e.g., changing to naming or structure of >>> the API in a non-backward-compatible way). >>> *No information provided* >>> >>> *Link to entry on the Chrome Platform Status* >>> https://chromestatus.com/feature/5071131271888896?gate=6546259918848000 >>> >>> This intent message was generated by Chrome Platform Status >>> <https://chromestatus.com/>. >>> >> -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6fa4b7b0-2e47-47c8-8017-49409c5de18an%40chromium.org > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/6fa4b7b0-2e47-47c8-8017-49409c5de18an%40chromium.org?utm_medium=email&utm_source=footer> > . > > -- > You received this message because you are subscribed to the Google Groups > "blink-dev" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To view this discussion visit > https://groups.google.com/a/chromium.org/d/msgid/blink-dev/fb2bb9ed-4a64-455e-be6d-de19626a80c4%40chromium.org > <https://groups.google.com/a/chromium.org/d/msgid/blink-dev/fb2bb9ed-4a64-455e-be6d-de19626a80c4%40chromium.org?utm_medium=email&utm_source=footer> > . > -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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