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conformance · v142

v142 · stricter-json-mime-token-validation-for-json-modules — conformance probe

6 assertions drawn from the spec. Each is a single contract the spec text makes. Pass/fail reflects what this browser executed; blocked means the contract was not run because it needs user mediation, hardware, or another unavailable precondition. Open the page in Chrome stable / canary / Firefox / Safari to compare.

browser: spec: https://mimesniff.spec.whatwg.org/#parse-a-mime-type chromestatus: #5182756304846848 generated 2026-06-01T08:13:10Z by conformance-author-v1-subagent
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id contract kind verdict detail
dynamic-import-exists Dynamic import() is the entry point for JSON module loads; the syntax is parsed without throwing. script
import-with-type-json-supported The import attributes (`with { type: 'json' }`) syntax is supported as the way to mark a JSON module. script
json-with-plus-json-suffix-still-accepted A response with a well-formed `*+json` MIME (no whitespace in type/subtype) still loads as a JSON module. script
json-mime-with-space-rejected A JSON module load whose MIME type contains a non-token code point (e.g. a space inside the subtype) is now rejected — the import promise rejects. spec ↗ script
json-mime-tab-in-type-rejected Likewise a tab character in the MIME type is rejected by the stricter validator. script
fetch-still-tolerates-loose-mime Fetch itself does not reject responses with loose MIME types — the strict check is module-loader-specific. typeof