Refactor add.ts by ije · Pull Request #3 · esm-dev/import-map

ije · 2026-03-01T11:06:57Z

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Copilot

Pull request overview

Refactors src/add.ts to reorganize fetch/meta handling and parsing logic for esm.sh import specifiers/paths as part of the import-map “add import from CDN” workflow.

Changes:

Makes ImportInfo/ImportMeta fields optional and updates dependency iteration to handle missing imports/peerImports.
Refactors fetch/meta caching and introduces META_CACHE_MEMO plus a module-level overridable fetcher via setFetcher.
Reworks specifier/path parsing and extends registry prefix handling (including a new pr://pr/ registry prefix).

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Copilot · 2026-03-01T11:11:10Z

src/add.ts

+  } else if (source.startsWith("pr:")) {
+    imp.pr = true;
+    source = source.slice(3);
  }


pr: is parsed and registryPrefix() supports it, but specifierOf() / esmSpecifierOf() don’t include a pr:/pr/ prefix and fetchImportMeta() doesn’t propagate pr onto the returned ImportMeta. As a result, pr: imports can collide with npm imports and may lose their registry identity after the first meta fetch; please thread pr through and include it in specifier/url prefix generation consistently.

Copilot · 2026-03-01T11:11:10Z

src/add.ts

+    [pkgNameNoScope, pkgVersion] = seg0.split("@", 2);
+    imp.name = pkgNameNoScope;
+    imp.version = pkgVersion;
+    hasTargetSegment = ESM_TARGETS.has(segs[1]);
+    subPath = segs.slice(hasTargetSegment ? 2 : 1).join("/");


GitHub/PR packages are encoded in URLs as /<registry>/<owner>/<repo>@<ver>/... (because imp.name contains a /), but this parser treats only segs[0] as the package segment. For /gh/owner/repo@tag/... this will set name="owner" and push the rest into subPath, producing incorrect specifiers and version comparisons; parseEsmPath should special-case imp.github/imp.pr to combine the first two segments into <owner>/<repo> + version (and then parse target/subpath).

Suggested change

[pkgNameNoScope, pkgVersion] = seg0.split("@", 2);

imp.name = pkgNameNoScope;

imp.version = pkgVersion;

hasTargetSegment = ESM_TARGETS.has(segs[1]);

subPath = segs.slice(hasTargetSegment ? 2 : 1).join("/");

if (imp.github || imp.pr) {

const seg1 = segs[1];

if (!seg1) {

throw new Error("invalid pathname: " + pathnameOrUrl);

}

[pkgNameNoScope, pkgVersion] = seg1.split("@", 2);

imp.name = seg0 + "/" + pkgNameNoScope;

imp.version = pkgVersion;

hasTargetSegment = ESM_TARGETS.has(segs[2]);

subPath = segs.slice(hasTargetSegment ? 3 : 2).join("/");

} else {

[pkgNameNoScope, pkgVersion] = seg0.split("@", 2);

imp.name = pkgNameNoScope;

imp.version = pkgVersion;

hasTargetSegment = ESM_TARGETS.has(segs[1]);

subPath = segs.slice(hasTargetSegment ? 2 : 1).join("/");

}

src/add.ts

Copilot · 2026-03-01T11:11:10Z

src/add.ts

+  let [maybePkgNameAndVersion, ...subPath] = source.split("/");
+  let [pkgNameNoScope, pkgVersion] = maybePkgNameAndVersion.split("@", 2);
+  if (scopeName) {
+    imp.name = scopeName + "/" + pkgNameNoScope;
+    imp.version = pkgVersion;
+  } else {
+    imp.name = pkgNameNoScope;
+    imp.version = pkgVersion;
+  }


pkgVersion can be undefined when the specifier has no @version (e.g. react), but it’s assigned into imp.version (typed as string). This can later produce URLs/specifiers containing the string "undefined" and breaks type expectations; default pkgVersion to an empty string or explicitly validate/throw when missing.

Copilot · 2026-03-01T11:11:11Z

src/add.ts

+    [pkgNameNoScope, pkgVersion] = segs[1].split("@", 2);
+    imp.name = seg0 + "/" + pkgNameNoScope;
+    imp.version = pkgVersion;
+    hasTargetSegment = ESM_TARGETS.has(segs[2]);
+    subPath = segs.slice(hasTargetSegment ? 3 : 2).join("/");
+  } else {
+    [pkgNameNoScope, pkgVersion] = seg0.split("@", 2);


parseEsmPath splits segs[1] by @ and assigns pkgVersion into imp.version, but pkgVersion can be undefined when there is no @ in the segment. This can propagate an undefined version into later URL/specifier generation; consider defaulting to "" (matching previous behavior) or throwing on missing versions.

Suggested change

[pkgNameNoScope, pkgVersion] = segs[1].split("@", 2);

imp.name = seg0 + "/" + pkgNameNoScope;

imp.version = pkgVersion;

hasTargetSegment = ESM_TARGETS.has(segs[2]);

subPath = segs.slice(hasTargetSegment ? 3 : 2).join("/");

} else {

[pkgNameNoScope, pkgVersion] = seg0.split("@", 2);

const scopedParts = segs[1].split("@", 2);

pkgNameNoScope = scopedParts[0];

pkgVersion = scopedParts[1] ?? "";

imp.name = seg0 + "/" + pkgNameNoScope;

imp.version = pkgVersion;

hasTargetSegment = ESM_TARGETS.has(segs[2]);

subPath = segs.slice(hasTargetSegment ? 3 : 2).join("/");

} else {

const unscopedParts = seg0.split("@", 2);

pkgNameNoScope = unscopedParts[0];

pkgVersion = unscopedParts[1] ?? "";

Copilot · 2026-03-01T11:11:11Z

src/add.ts

+    [pkgNameNoScope, pkgVersion] = seg0.split("@", 2);
+    imp.name = pkgNameNoScope;
+    imp.version = pkgVersion;
+    hasTargetSegment = ESM_TARGETS.has(segs[1]);
+    subPath = segs.slice(hasTargetSegment ? 2 : 1).join("/");


parseEsmPath splits seg0 by @ and assigns pkgVersion into imp.version, but pkgVersion can be undefined when there is no @ in the segment. This can propagate an undefined version into later URL/specifier generation; consider defaulting to "" (matching previous behavior) or throwing on missing versions.

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

…ests

Copilot

Pull request overview

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

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Copilot · 2026-03-01T11:38:33Z

src/add.ts

+  if (imp.github) {
+    prefix = "github:";
+  } else if (imp.jsr) {
+    prefix = "jsr:";
+  } else if (imp.pr) {
+    prefix = "pr:";
+  }


specifierOf now canonicalizes GitHub specifiers to github:. This breaks the documented/public specifier form (gh:owner/repo@tag) and can lead to duplicate keys (e.g., user passes gh:... but the import map key becomes github:..., so existing gh: entries won’t be found). Consider keeping gh: as the canonical output (optionally still accepting github: as an input alias), or update the public API/docs consistently.

Copilot · 2026-03-01T11:38:34Z

src/add.ts

      github: imp.github,
      jsr: imp.jsr,
+      pr: imp.pr,
      external: imp.external,
      dev: imp.dev,


pr: imp.pr is propagated into the returned ImportMeta, but updateIntegrity()’s follow-up fetchImportMeta call for external: true doesn’t include pr. For pr: packages that require the external-meta integrity lookup, this will fetch from the wrong registry path and can produce incorrect integrity entries. Ensure the integrity lookup passes pr: imp.pr as well (and consider adding a test for this path).

Copilot · 2026-03-01T11:38:34Z

src/add.ts

+    [pkgNameNoScope, pkgVersion] = seg0.split("@", 2);
+    imp.name = pkgNameNoScope;
+    imp.version = pkgVersion;
+    hasTargetSegment = ESM_TARGETS.has(segs[1]);
+    subPath = segs.slice(hasTargetSegment ? 2 : 1).join("/");


parseEsmPath doesn’t correctly parse GitHub CDN paths like /gh/owner/repo@tag/... where the package name spans two path segments. In the non-scoped branch, seg0 becomes owner (no version), so imp.name/imp.version end up wrong and subPath becomes repo@tag/.... Consider a special-case when imp.github is true (and seg0 is not scoped) to combine segs[0] + / + segs[1] (splitting version from segs[1]) before checking for the target segment.

Suggested change

[pkgNameNoScope, pkgVersion] = seg0.split("@", 2);

imp.name = pkgNameNoScope;

imp.version = pkgVersion;

hasTargetSegment = ESM_TARGETS.has(segs[1]);

subPath = segs.slice(hasTargetSegment ? 2 : 1).join("/");

if (imp.github) {

if (!segs[1]) {

throw new Error("invalid pathname: " + pathnameOrUrl);

}

[pkgNameNoScope, pkgVersion] = segs[1].split("@", 2);

imp.name = seg0 + "/" + pkgNameNoScope;

imp.version = pkgVersion;

hasTargetSegment = ESM_TARGETS.has(segs[2]);

subPath = segs.slice(hasTargetSegment ? 3 : 2).join("/");

} else {

[pkgNameNoScope, pkgVersion] = seg0.split("@", 2);

imp.name = pkgNameNoScope;

imp.version = pkgVersion;

hasTargetSegment = ESM_TARGETS.has(segs[1]);

subPath = segs.slice(hasTargetSegment ? 2 : 1).join("/");

}

Refactor add.ts

730171b

Copilot AI review requested due to automatic review settings March 1, 2026 11:06

Copilot started reviewing on behalf of ije March 1, 2026 11:07 View session

Copilot AI reviewed Mar 1, 2026

View reviewed changes

ije and others added 2 commits March 1, 2026 19:22

Update src/add.ts

2f44572

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Add support for 'pr' prefix in import specifiers and update related t…

03cc530

…ests

ije requested a review from Copilot March 1, 2026 11:34

Copilot started reviewing on behalf of ije March 1, 2026 11:34 View session

Copilot AI reviewed Mar 1, 2026

View reviewed changes

ije added 3 commits March 1, 2026 21:23

remove pr prefix

a271b8e

fix

4fca4bb

fix test

32d73b7

ije merged commit 7053781 into main Mar 1, 2026
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Refactor add.ts#3

Refactor add.ts#3
ije merged 6 commits intomainfrom
refactor

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ije commented Mar 1, 2026

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