feat(sandbox): add util to QuickJS module registry - #10374
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Ports node:util's format/promisify/types.is* as a pure-JS reimplementation, verified for parity against real node:util (including format's -0/bigint/symbol coercion quirks and quote-selection). util.inspect/inherits/deprecate and %o's showHidden/depth-4 behavior are explicitly out of scope — documented in PERMISSIONS.md.
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✅ Circular References ReportGenerated at: 2026-08-11T14:21:39.088Z Summary
Click to view all circular references in PR (9)Click to view all circular references in base branch (9)Analysis✅ No Change: This PR does not introduce or remove any circular references. This report was generated automatically by comparing against the |
…-spoofability in PERMISSIONS.md Found by the independent security review: unlike the rest of types.is*, these two use Object.prototype.toString.call (no instanceof target exists for either), so a value with a forged Symbol.toStringTag can produce a wrong boolean — a correctness gap, not a capability leak.
kwburns-kong
marked this pull request as ready for review
August 11, 2026 14:09
Removes eval() from the format() parity test's literal-value comparisons (Semgrep javascript.browser.security.eval-detected) by building the real node:util comparison value directly instead of eval'ing the same source text used for the sandboxed side. Documents and suppresses the CodeQL js/bad-code-sanitization finding on runBody's plugin-source construction — body is always a fixed literal from within this file (never external input) and is expected to contain arbitrary JS syntax, including quote/backtick characters that a generic sanitizer would corrupt.
| // disposable, isolated QuickJS sandbox this whole file is testing, never on the host. | ||
| const runBody = (body: string) => | ||
| runTagInSandbox({ | ||
| pluginSource: `module.exports.templateTags = [{ name: 'r', run: function () { ${body} } }];`, // lgtm[js/bad-code-sanitization] |
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Ports
format,promisify, andtypes.is*fromnode:utilas a pure-JS reimplementation in the QuickJS plugin sandbox, per the module-porting plan's reduced-scope entry forutil.format: verified against realnode:utilacross all specifiers (%s %d %i %f %j %o %O %c %%), including the-0/bigint/symbol coercion quirks and the quote-character selection used for inspected strings.promisify: error/multi-value/Symbol.for("nodejs.util.promisify.custom")override semantics verified against realnode:util.types.is*: implemented viainstanceof(immune toSymbol.toStringTagspoofing) rather thanObject.prototype.toString.call, exceptisAsyncFunction/isGeneratorFunction(documented in PERMISSIONS.md).util.inspect/inherits/deprecateare not implemented;%ois aliased to%O's bounded-depth behavior rather than replicating real Node's showHidden/depth-4/proxy inspection.Independent security review found no capability leaks or sandbox-escape paths; one documentation gap (isAsyncFunction/isGeneratorFunction's toStringTag-spoofability wasn't noted in PERMISSIONS.md) was fixed inline.