fix: selectively import required semver functions (#511)

By selectively importing only the functions and classes we use, we avoid bundling in the entire semver package, and shave a few kB off from the Corepack bundle.

Author: wojtekmaj

genlist.ts

@@ -1,10 +1,10 @@
 import {readFileSync} from 'fs';
-import semver         from 'semver';
+import semverCompare  from 'semver/functions/compare';
 
 const lines = readFileSync(0, `utf8`).split(/\n/).filter(line => line);
 
 lines.sort((a, b) => {
-  return semver.compare(a, b);
+  return semverCompare(a, b);
 });
 
 for (const version of lines)

sources/Engine.ts

@@ -2,7 +2,9 @@ import {UsageError}                                           from 'clipanion';
 import fs                                                     from 'fs';
 import path                                                   from 'path';
 import process                                                from 'process';
-import semver                                                 from 'semver';
+import semverRcompare                                         from 'semver/functions/rcompare';
+import semverValid                                            from 'semver/functions/valid';
+import semverValidRange                                       from 'semver/ranges/valid';
 
 import defaultConfig                                          from '../config.json';
 
@@ -334,7 +336,7 @@ export class Engine {
       throw new UsageError(`This package manager (${descriptor.name}) isn't supported by this corepack build`);
 
     let finalDescriptor = descriptor;
-    if (!semver.valid(descriptor.range) && !semver.validRange(descriptor.range)) {
+    if (!semverValid(descriptor.range) && !semverValidRange(descriptor.range)) {
       if (!allowTags)
         throw new UsageError(`Packages managers can't be referenced via tags in this context`);
 
@@ -363,7 +365,7 @@ export class Engine {
 
     // If the user asked for a specific version, no need to request the list of
     // available versions from the registry.
-    if (semver.valid(finalDescriptor.range))
+    if (semverValid(finalDescriptor.range))
       return {name: finalDescriptor.name, reference: finalDescriptor.range};
 
     const versions = await Promise.all(Object.keys(definition.ranges).map(async range => {
@@ -374,7 +376,7 @@ export class Engine {
       return versions.filter(version => semverUtils.satisfiesWithPrereleases(version, finalDescriptor.range));
     }));
 
-    const highestVersion = [...new Set(versions.flat())].sort(semver.rcompare);
+    const highestVersion = [...new Set(versions.flat())].sort(semverRcompare);
     if (highestVersion.length === 0)
       return null;
 

sources/commands/Up.ts

@@ -1,5 +1,7 @@
 import {Command, UsageError}           from 'clipanion';
-import semver                          from 'semver';
+import semverMajor                     from 'semver/functions/major';
+import semverValid                     from 'semver/functions/valid';
+import semverValidRange                from 'semver/ranges/valid';
 
 import type {SupportedPackageManagers} from '../types';
 
@@ -33,14 +35,14 @@ export class UpCommand extends BaseCommand {
       patterns: [],
     });
 
-    if (!semver.valid(descriptor.range) && !semver.validRange(descriptor.range))
+    if (!semverValid(descriptor.range) && !semverValidRange(descriptor.range))
       throw new UsageError(`The 'corepack up' command can only be used when your project's packageManager field is set to a semver version or semver range`);
 
     const resolved = await this.context.engine.resolveDescriptor(descriptor, {useCache: false});
     if (!resolved)
       throw new UsageError(`Failed to successfully resolve '${descriptor.range}' to a valid ${descriptor.name} release`);
 
-    const majorVersion = semver.major(resolved.reference);
+    const majorVersion = semverMajor(resolved.reference);
     const majorDescriptor = {name: descriptor.name as SupportedPackageManagers, range: `^${majorVersion}.0.0`};
 
     const highestVersion = await this.context.engine.resolveDescriptor(majorDescriptor, {useCache: false});

sources/corepackUtils.ts

@@ -4,7 +4,10 @@ import fs                                                      from 'fs';
 import type {Dir}                                              from 'fs';
 import Module                                                  from 'module';
 import path                                                    from 'path';
-import semver                                                  from 'semver';
+import Range                                                   from 'semver/classes/range';
+import SemVer                                                  from 'semver/classes/semver';
+import semverLt                                                from 'semver/functions/lt';
+import semverParse                                             from 'semver/functions/parse';
 import {setTimeout as setTimeoutPromise}                       from 'timers/promises';
 
 import * as engine                                             from './Engine';
@@ -82,9 +85,9 @@ export async function findInstalledVersion(installTarget: string, descriptor: De
     }
   }
 
-  const range = new semver.Range(descriptor.range);
+  const range = new Range(descriptor.range);
   let bestMatch: string | null = null;
-  let maxSV: semver.SemVer | undefined = undefined;
+  let maxSV: SemVer | undefined = undefined;
 
   for await (const {name} of cacheDirectory) {
     // Some dot-folders tend to pop inside directories, especially on OSX
@@ -97,7 +100,7 @@ export async function findInstalledVersion(installTarget: string, descriptor: De
     // @ts-expect-error TODO: decipher why this produces an error
     if (range.test(name) && maxSV?.compare(name) !== 1) {
       bestMatch = name;
-      maxSV = new semver.SemVer(bestMatch);
+      maxSV = new SemVer(bestMatch);
     }
   }
 
@@ -193,7 +196,7 @@ async function download(installTarget: string, url: string, algo: string, binPat
 
 export async function installVersion(installTarget: string, locator: Locator, {spec}: {spec: PackageManagerSpec}): Promise<InstallSpec> {
   const locatorIsASupportedPackageManager = isSupportedPackageManagerLocator(locator);
-  const locatorReference = locatorIsASupportedPackageManager ? semver.parse(locator.reference)! : parseURLReference(locator);
+  const locatorReference = locatorIsASupportedPackageManager ? semverParse(locator.reference)! : parseURLReference(locator);
   const {version, build} = locatorReference;
 
   const installFolder = path.join(installTarget, locator.name, version);
@@ -326,9 +329,9 @@ export async function installVersion(installTarget: string, locator: Locator, {s
     const lastKnownGood = await engine.getLastKnownGood();
     const defaultVersion = engine.getLastKnownGoodFromFileContent(lastKnownGood, locator.name);
     if (defaultVersion) {
-      const currentDefault = semver.parse(defaultVersion)!;
-      const downloadedVersion = locatorReference as semver.SemVer;
-      if (currentDefault.major === downloadedVersion.major && semver.lt(currentDefault, downloadedVersion)) {
+      const currentDefault = semverParse(defaultVersion)!;
+      const downloadedVersion = locatorReference as SemVer;
+      if (currentDefault.major === downloadedVersion.major && semverLt(currentDefault, downloadedVersion)) {
         await engine.activatePackageManager(lastKnownGood, locator);
       }
     }
@@ -404,7 +407,7 @@ export async function runVersion(locator: Locator, installSpec: InstallSpec & {s
   // Node.js segfaults when using npm@>=9.7.0 and v8-compile-cache
   // $ docker run -it node:20.3.0-slim corepack npm@9.7.1 --version
   // [SIGSEGV]
-  if (locator.name !== `npm` || semver.lt(locator.reference, `9.7.0`))
+  if (locator.name !== `npm` || semverLt(locator.reference, `9.7.0`))
     // @ts-expect-error - No types
     await import(`v8-compile-cache`);
 

sources/semverUtils.ts

@@ -1,4 +1,5 @@
-import semver from 'semver';
+import Range  from 'semver/classes/range';
+import SemVer from 'semver/classes/semver';
 
 /**
  * Returns whether the given semver version satisfies the given range. Notably
@@ -16,17 +17,17 @@ import semver from 'semver';
 export function satisfiesWithPrereleases(version: string | null, range: string, loose: boolean = false): boolean {
   let semverRange;
   try {
-    semverRange = new semver.Range(range, loose);
+    semverRange = new Range(range, loose);
   } catch (err) {
     return false;
   }
 
   if (!version)
     return false;
 
-  let semverVersion: semver.SemVer;
+  let semverVersion: SemVer;
   try {
-    semverVersion = new semver.SemVer(version, semverRange.loose);
+    semverVersion = new SemVer(version, semverRange.loose);
     if (semverVersion.prerelease) {
       semverVersion.prerelease = [];
     }

sources/specUtils.ts

@@ -1,7 +1,7 @@
 import {UsageError}                            from 'clipanion';
 import fs                                      from 'fs';
 import path                                    from 'path';
-import semver                                  from 'semver';
+import semverValid                             from 'semver/functions/valid';
 
 import {PreparedPackageManagerInfo}            from './Engine';
 import {NodeError}                             from './nodeUtils';
@@ -34,7 +34,7 @@ export function parseSpec(raw: unknown, source: string, {enforceExactVersion = t
 
   const isURL = URL.canParse(range);
   if (!isURL) {
-    if (enforceExactVersion && !semver.valid(range))
+    if (enforceExactVersion && !semverValid(range))
       throw new UsageError(`Invalid package manager specification in ${source} (${raw}); expected a semver version${enforceExactVersion ? `` : `, range, or tag`}`);
 
     if (!isSupportedPackageManager(name)) {