fix: report n for no-substitution template dynamic imports#201
Merged
guybedford merged 2 commits intoJun 21, 2026
Merged
Conversation
A dynamic import whose specifier is a no-substitution template literal
(import(`./x.js`)) returned n: undefined, while the quoted forms returned the
specifier. A template with no ${...} is a constant string, so it now records a
safe specifier the same as a quoted one; an interpolated template has no
constant value and still returns undefined. This surfaces with minified
Rolldown bundles, which rewrite dynamic-import specifiers to template literals.
readString tolerates raw line breaks for a backtick quote, since template
literals permit them and string literals do not.
Drive-by fix:
* The JS fallback recorded the specifier start before skipping leading
whitespace/comments, so import(/* c */ "x") mis-decoded n; it now records the
start after, matching the C lexer.
Fixes guybedford#198
The asm.js wrapper decodes the dynamic-import specifier with its own readString copy, which still rejected raw line breaks. A multi-line no-substitution template threw a parse error on the asm.js build while WASM and the JS fallback decoded it. Apply the same backtick exception.
mergify Bot
added a commit
to ArcadeData/arcadedb
that referenced
this pull request
Jul 5, 2026
…2.3.0 in /studio [skip ci] Bumps [es-module-lexer](https://github.com/guybedford/es-module-lexer) from 2.1.0 to 2.3.0. Release notes *Sourced from [es-module-lexer's releases](https://github.com/guybedford/es-module-lexer/releases).* > 2.2.0 > ----- > > What's Changed > -------------- > > * build(deps-dev): update dev dependencies to latest by [`@BridgeAR`](https://github.com/BridgeAR) in [guybedford/es-module-lexer#200](https://redirect.github.com/guybedford/es-module-lexer/pull/200) > * fix: report n for no-substitution template dynamic imports by [`@BridgeAR`](https://github.com/BridgeAR) in [guybedford/es-module-lexer#201](https://redirect.github.com/guybedford/es-module-lexer/pull/201) > * Automatic asm.js dictionary extraction and clang toolchain update by [`@guybedford`](https://github.com/guybedford) in [guybedford/es-module-lexer#203](https://redirect.github.com/guybedford/es-module-lexer/pull/203) > * fix: don't treat a method named `import` with 2+ args as a dynamic import by [`@soberm`](https://github.com/soberm) in [guybedford/es-module-lexer#207](https://redirect.github.com/guybedford/es-module-lexer/pull/207) > * fix: detect every binding in export var/let/const declarations by [`@BridgeAR`](https://github.com/BridgeAR) in [guybedford/es-module-lexer#199](https://redirect.github.com/guybedford/es-module-lexer/pull/199) > * feat: expose export statement start position as ss by [`@BridgeAR`](https://github.com/BridgeAR) in [guybedford/es-module-lexer#206](https://redirect.github.com/guybedford/es-module-lexer/pull/206) > > New Contributors > ---------------- > > * [`@BridgeAR`](https://github.com/BridgeAR) made their first contribution in [guybedford/es-module-lexer#200](https://redirect.github.com/guybedford/es-module-lexer/pull/200) > * [`@soberm`](https://github.com/soberm) made their first contribution in [guybedford/es-module-lexer#207](https://redirect.github.com/guybedford/es-module-lexer/pull/207) > > **Full Changelog**: <guybedford/es-module-lexer@2.1.0...2.2.0> Commits * [`dbac1c3`](guybedford/es-module-lexer@dbac1c3) 2.3.0 * [`f3c972d`](guybedford/es-module-lexer@f3c972d) fix: allow wasm memory growth in the minimal build, document it in the readme... * [`e9b611e`](guybedford/es-module-lexer@e9b611e) fix: allow wasm memory growth for sources over ~4MB ([#217](https://redirect.github.com/guybedford/es-module-lexer/issues/217)) * [`6c90425`](guybedford/es-module-lexer@6c90425) feat: add minimal build for es-module-shims (es-module-lexer/minimal) ([#211](https://redirect.github.com/guybedford/es-module-lexer/issues/211)) * [`70010fb`](guybedford/es-module-lexer@70010fb) docs: correct stale limitations and gzip size in README ([#212](https://redirect.github.com/guybedford/es-module-lexer/issues/212)) * [`1f19494`](guybedford/es-module-lexer@1f19494) 2.2.0 * [`d61e97a`](guybedford/es-module-lexer@d61e97a) feat: expose export statement start position as ss ([#206](https://redirect.github.com/guybedford/es-module-lexer/issues/206)) * [`064d0db`](guybedford/es-module-lexer@064d0db) fix: detect every binding in export var/let/const declarations ([#199](https://redirect.github.com/guybedford/es-module-lexer/issues/199)) * [`99b5226`](guybedford/es-module-lexer@99b5226) fix: don't treat a method named `import` with 2+ args as a dynamic import ([#207](https://redirect.github.com/guybedford/es-module-lexer/issues/207)) * [`fa1ade6`](guybedford/es-module-lexer@fa1ade6) build: update to upstream emsdk toolchain and derive asm.js dictionary from t... * Additional commits viewable in [compare view](guybedford/es-module-lexer@2.1.0...2.3.0) [](https://docs.github.com/en/github/managing-security-vulnerabilities/about-dependabot-security-updates#about-compatibility-scores) Dependabot will resolve any conflicts with this PR as long as you don't alter it yourself. You can also trigger a rebase manually by commenting `@dependabot rebase`. [//]: # (dependabot-automerge-start) [//]: # (dependabot-automerge-end) --- Dependabot commands and options You can trigger Dependabot actions by commenting on this PR: - `@dependabot rebase` will rebase this PR - `@dependabot recreate` will recreate this PR, overwriting any edits that have been made to it - `@dependabot show ignore conditions` will show all of the ignore conditions of the specified dependency - `@dependabot ignore this major version` will close this PR and stop Dependabot creating any more for this major version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this minor version` will close this PR and stop Dependabot creating any more for this minor version (unless you reopen the PR or upgrade to it yourself) - `@dependabot ignore this dependency` will close this PR and stop Dependabot creating any more for this dependency (unless you reopen the PR or upgrade to it yourself)
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
2 participants
Add this suggestion to a batch that can be applied as a single commit.This suggestion is invalid because no changes were made to the code.Suggestions cannot be applied while the pull request is closed.Suggestions cannot be applied while viewing a subset of changes.Only one suggestion per line can be applied in a batch.Add this suggestion to a batch that can be applied as a single commit.Applying suggestions on deleted lines is not supported.You must change the existing code in this line in order to create a valid suggestion.Outdated suggestions cannot be applied.This suggestion has been applied or marked resolved.Suggestions cannot be applied from pending reviews.Suggestions cannot be applied on multi-line comments.Suggestions cannot be applied while the pull request is queued to merge.Suggestion cannot be applied right now. Please check back later.
Summary
A dynamic import whose specifier is a no-substitution template literal
(
import(`./x.js`)) returnedn: undefined, while the quoted formsreturned the specifier. A template with no
${...}is a constant string, so itnow records a safe specifier the same as a quoted one; an interpolated template
has no constant value and still returns
undefined. This surfaces with minifiedRolldown bundles, which rewrite dynamic-import specifiers to template literals.
src/lexer.cand thelexer.jsfallback are updated together.readStringtolerates raw line breaks for a backtick quote, since template literals permit
them and string literals do not.
Drive-by
lexer.jsfallback recorded the specifier start before skipping leadingwhitespace/comments, so
import(/* c */ "x")mis-decodedn; it now recordsthe start after, matching the C lexer.
Test plan
chomp test(WASM + ASM): newDynamic import …template specifiercasesin
test/_unit.cjs(quoted vs no-substitution vs interpolated, escapes,attributes, multi-line)
Fixes #198