Fix circular peer dependencies blocking updates

src/lib/getPeerDependenciesFromRegistry.ts

@@ -1,8 +1,10 @@
 import ProgressBar from 'progress'
+import nodeSemver from 'semver'
 import { Index } from '../types/IndexType'
 import { Options } from '../types/Options'
 import { VersionSpec } from '../types/VersionSpec'
 import getPackageManager from './getPackageManager'
+import { isCircularPeer } from './isCircularPeer'
 
 /**
  * Get the latest or greatest versions from the NPM repository based on the version target.
@@ -22,14 +24,23 @@ async function getPeerDependenciesFromRegistry(packageMap: Index<VersionSpec>, o
     bar.render()
   }
 
-  return Object.entries(packageMap).reduce(async (accumPromise, [pkg, version]) => {
-    const dep = await packageManager.getPeerDependencies!(pkg, version)
-    if (bar) {
-      bar.tick()
-    }
-    const accum = await accumPromise
-    return { ...accum, [pkg]: dep }
-  }, {})
+  const peerDependencies: Index<Index<string>> = Object.entries(packageMap).reduce(
+    async (accumPromise, [pkg, version]) => {
+      const dep = await packageManager.getPeerDependencies!(pkg, nodeSemver.coerce(version)?.version ?? version)
+      if (bar) {
+        bar.tick()
+      }
+      const accum = await accumPromise
+      const newAcc: Index<Index<string>> = { ...accum, [pkg]: dep }
+      const circularData = isCircularPeer(newAcc, pkg)
+      if (circularData.isCircular) {
+        delete newAcc[pkg][circularData.offendingPackage]
+      }
+      return newAcc
+    },
+    {},
+  )
+  return peerDependencies
 }
 
 export default getPeerDependenciesFromRegistry

src/lib/isCircularPeer.ts

@@ -0,0 +1,38 @@
+import { Index } from '../types/IndexType'
+
+type CircularData =
+  | {
+      isCircular: true
+      offendingPackage: string
+    }
+  | {
+      isCircular: false
+    }
+
+/**
+ * Checks if the specified package will create a loop of peer dependencies by traversing all paths to find a cycle
+ *
+ * If a cycle was found, the offending peer dependency of the specified package is returned
+ */
+export function isCircularPeer(peerDependencies: Index<Index<string>>, packageName: string): CircularData {
+  let queue = [[packageName]]
+  while (queue.length > 0) {
+    const nextQueue: string[][] = []
+    for (const path of queue) {
+      const parents = Object.keys(peerDependencies[path[0]] ?? {})
+      for (const name of parents) {
+        if (name === path.at(-1)) {
+          return {
+            isCircular: true,
+            offendingPackage: path[0],
+          }
+        }
+        nextQueue.push([name, ...path])
+      }
+    }
+    queue = nextQueue
+  }
+  return {
+    isCircular: false,
+  }
+}

src/lib/runLocal.ts

@@ -15,7 +15,7 @@ import chalk from './chalk'
 import getCurrentDependencies from './getCurrentDependencies'
 import getIgnoredUpgrades from './getIgnoredUpgrades'
 import getPackageManager from './getPackageManager'
-import getPeerDependencies from './getPeerDependencies'
+import getPeerDependenciesFromRegistry from './getPeerDependenciesFromRegistry'
 import keyValueBy from './keyValueBy'
 import { print, printIgnoredUpdates, printJson, printSorted, printUpgrades, toDependencyTable } from './logging'
 import programError from './programError'
@@ -183,7 +183,7 @@ async function runLocal(
   }
 
   if (options.peer) {
-    options.peerDependencies = await getPeerDependencies(current, options)
+    options.peerDependencies = await getPeerDependenciesFromRegistry(current, options)
   }
 
   const [upgraded, latestResults, upgradedPeerDependencies] = await upgradePackageDefinitions(current, options)

test/peer.test.ts

@@ -1,52 +1,38 @@
-import fs from 'fs/promises'
 import path from 'path'
 import ncu from '../src/'
-import spawnNpm from '../src/package-managers/npm'
 import chaiSetup from './helpers/chaiSetup'
 
 chaiSetup()
 
 describe('peer dependencies', function () {
   it('peer dependencies of installed packages are ignored by default', async () => {
     const cwd = path.join(__dirname, 'test-data/peer/')
-    try {
-      await spawnNpm('install', {}, {}, { cwd })
-      const upgrades = await ncu({ cwd })
-      upgrades!.should.deep.equal({
-        'ncu-test-return-version': '2.0.0',
-      })
-    } finally {
-      await fs.rm(path.join(cwd, 'node_modules'), { recursive: true, force: true })
-      await fs.rm(path.join(cwd, 'package-lock.json'), { recursive: true, force: true })
-    }
+    const upgrades = await ncu({ cwd })
+    upgrades!.should.deep.equal({
+      'ncu-test-return-version': '2.0.0',
+    })
   })
 
   it('peer dependencies of installed packages are checked when using option peer', async () => {
     const cwd = path.join(__dirname, 'test-data/peer/')
-    try {
-      await spawnNpm('install', {}, {}, { cwd })
-      const upgrades = await ncu({ cwd, peer: true })
-      upgrades!.should.deep.equal({
-        'ncu-test-return-version': '1.1.0',
-      })
-    } finally {
-      await fs.rm(path.join(cwd, 'node_modules'), { recursive: true, force: true })
-      await fs.rm(path.join(cwd, 'package-lock.json'), { recursive: true, force: true })
-    }
+    const upgrades = await ncu({ cwd, peer: true })
+    upgrades!.should.deep.equal({
+      'ncu-test-return-version': '1.1.0',
+    })
   })
 
   it('peer dependencies of installed packages are checked iteratively when using option peer', async () => {
     const cwd = path.join(__dirname, 'test-data/peer-update/')
-    try {
-      await spawnNpm('install', {}, {}, { cwd })
-      const upgrades = await ncu({ cwd, peer: true })
-      upgrades!.should.deep.equal({
-        'ncu-test-return-version': '1.1.0',
-        'ncu-test-peer-update': '1.1.0',
-      })
-    } finally {
-      await fs.rm(path.join(cwd, 'node_modules'), { recursive: true, force: true })
-      await fs.rm(path.join(cwd, 'package-lock.json'), { recursive: true, force: true })
-    }
+    const upgrades = await ncu({ cwd, peer: true })
+    upgrades!.should.deep.equal({
+      'ncu-test-return-version': '1.1.0',
+      'ncu-test-peer-update': '1.1.0',
+    })
+  })
+
+  it('circular peer dependencies are ignored', async () => {
+    const cwd = path.join(__dirname, 'test-data/peer-lock/')
+    const upgrades = await ncu({ cwd, peer: true })
+    upgrades!.should.contain.keys('@vitest/ui', 'vitest')
   })
 })

test/test-data/peer-lock/package.json

@@ -0,0 +1,7 @@
+{
+  "license": "MIT",
+  "dependencies": {
+    "@vitest/ui": "^1.3.1",
+    "vitest": "^1.3.1"
+  }
+}