fix: create links relative to the target

Added link deps need to be relative to the package they're being added
to, not the project root.  In the past the project root was the only
place you could add things but workspaces changed this.

workspaces/arborist/lib/arborist/build-ideal-tree.js

@@ -514,7 +514,9 @@ Try using the package name instead, e.g:
   // This returns a promise because we might not have the name yet,
   // and need to call pacote.manifest to find the name.
   async [_add] (tree, { add, saveType = null, saveBundle = false }) {
-    const path = this.idealTree.target.path
+    // If we have a link it will need to be added relative to the target's path
+    const path = tree.target.path
+
     // get the name for each of the specs in the list.
     // ie, doing `foo@bar` we just return foo
     // but if it's a url or git, we don't know the name until we

workspaces/arborist/tap-snapshots/test/arborist/build-ideal-tree.js.test.cjs

@@ -1470,6 +1470,207 @@ ArboristNode {
 }
 `
 
+exports[`test/arborist/build-ideal-tree.js TAP add one workspace to another > tree with workspace a added to workspace c 1`] = `
+ArboristNode {
+  "children": Map {
+    "a" => ArboristLink {
+      "edgesIn": Set {
+        EdgeIn {
+          "from": "",
+          "name": "a",
+          "spec": "file:{CWD}/test/fixtures/workspaces-not-root/packages/a",
+          "type": "workspace",
+        },
+        EdgeIn {
+          "from": "packages/c",
+          "name": "a",
+          "spec": "file:../a",
+          "type": "prod",
+        },
+      },
+      "isWorkspace": true,
+      "location": "node_modules/a",
+      "name": "a",
+      "path": "{CWD}/test/fixtures/workspaces-not-root/node_modules/a",
+      "realpath": "{CWD}/test/fixtures/workspaces-not-root/packages/a",
+      "resolved": "file:../packages/a",
+      "target": ArboristNode {
+        "location": "packages/a",
+      },
+      "version": "1.2.3",
+    },
+    "abbrev" => ArboristNode {
+      "edgesIn": Set {
+        EdgeIn {
+          "from": "",
+          "name": "abbrev",
+          "spec": "*",
+          "type": "prod",
+        },
+        EdgeIn {
+          "from": "packages/b",
+          "name": "abbrev",
+          "spec": "*",
+          "type": "prod",
+        },
+        EdgeIn {
+          "from": "packages/c",
+          "name": "abbrev",
+          "spec": "*",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/abbrev",
+      "name": "abbrev",
+      "path": "{CWD}/test/fixtures/workspaces-not-root/node_modules/abbrev",
+      "resolved": "https://registry.npmjs.org/abbrev/-/abbrev-1.1.1.tgz",
+      "version": "1.1.1",
+    },
+    "b" => ArboristLink {
+      "edgesIn": Set {
+        EdgeIn {
+          "from": "",
+          "name": "b",
+          "spec": "file:{CWD}/test/fixtures/workspaces-not-root/packages/b",
+          "type": "workspace",
+        },
+      },
+      "isWorkspace": true,
+      "location": "node_modules/b",
+      "name": "b",
+      "path": "{CWD}/test/fixtures/workspaces-not-root/node_modules/b",
+      "realpath": "{CWD}/test/fixtures/workspaces-not-root/packages/b",
+      "resolved": "file:../packages/b",
+      "target": ArboristNode {
+        "location": "packages/b",
+      },
+      "version": "1.2.3",
+    },
+    "c" => ArboristLink {
+      "edgesIn": Set {
+        EdgeIn {
+          "from": "",
+          "name": "c",
+          "spec": "file:{CWD}/test/fixtures/workspaces-not-root/packages/c",
+          "type": "workspace",
+        },
+      },
+      "isWorkspace": true,
+      "location": "node_modules/c",
+      "name": "c",
+      "path": "{CWD}/test/fixtures/workspaces-not-root/node_modules/c",
+      "realpath": "{CWD}/test/fixtures/workspaces-not-root/packages/c",
+      "resolved": "file:../packages/c",
+      "target": ArboristNode {
+        "location": "packages/c",
+      },
+      "version": "1.2.3",
+    },
+    "wrappy" => ArboristNode {
+      "edgesIn": Set {
+        EdgeIn {
+          "from": "",
+          "name": "wrappy",
+          "spec": "1.0.0",
+          "type": "prod",
+        },
+      },
+      "location": "node_modules/wrappy",
+      "name": "wrappy",
+      "path": "{CWD}/test/fixtures/workspaces-not-root/node_modules/wrappy",
+      "resolved": "https://registry.npmjs.org/wrappy/-/wrappy-1.0.0.tgz",
+      "version": "1.0.0",
+    },
+  },
+  "edgesOut": Map {
+    "a" => EdgeOut {
+      "name": "a",
+      "spec": "file:{CWD}/test/fixtures/workspaces-not-root/packages/a",
+      "to": "node_modules/a",
+      "type": "workspace",
+    },
+    "abbrev" => EdgeOut {
+      "name": "abbrev",
+      "spec": "*",
+      "to": "node_modules/abbrev",
+      "type": "prod",
+    },
+    "b" => EdgeOut {
+      "name": "b",
+      "spec": "file:{CWD}/test/fixtures/workspaces-not-root/packages/b",
+      "to": "node_modules/b",
+      "type": "workspace",
+    },
+    "c" => EdgeOut {
+      "name": "c",
+      "spec": "file:{CWD}/test/fixtures/workspaces-not-root/packages/c",
+      "to": "node_modules/c",
+      "type": "workspace",
+    },
+    "wrappy" => EdgeOut {
+      "name": "wrappy",
+      "spec": "1.0.0",
+      "to": "node_modules/wrappy",
+      "type": "prod",
+    },
+  },
+  "fsChildren": Set {
+    ArboristNode {
+      "isWorkspace": true,
+      "location": "packages/a",
+      "name": "a",
+      "path": "{CWD}/test/fixtures/workspaces-not-root/packages/a",
+      "version": "1.2.3",
+    },
+    ArboristNode {
+      "edgesOut": Map {
+        "abbrev" => EdgeOut {
+          "name": "abbrev",
+          "spec": "*",
+          "to": "node_modules/abbrev",
+          "type": "prod",
+        },
+      },
+      "isWorkspace": true,
+      "location": "packages/b",
+      "name": "b",
+      "path": "{CWD}/test/fixtures/workspaces-not-root/packages/b",
+      "version": "1.2.3",
+    },
+    ArboristNode {
+      "edgesOut": Map {
+        "a" => EdgeOut {
+          "name": "a",
+          "spec": "file:../a",
+          "to": "node_modules/a",
+          "type": "prod",
+        },
+        "abbrev" => EdgeOut {
+          "name": "abbrev",
+          "spec": "*",
+          "to": "node_modules/abbrev",
+          "type": "prod",
+        },
+      },
+      "isWorkspace": true,
+      "location": "packages/c",
+      "name": "c",
+      "path": "{CWD}/test/fixtures/workspaces-not-root/packages/c",
+      "version": "1.2.3",
+    },
+  },
+  "isProjectRoot": true,
+  "location": "",
+  "name": "workspaces-not-root",
+  "path": "{CWD}/test/fixtures/workspaces-not-root",
+  "workspaces": Map {
+    "a" => "packages/a",
+    "b" => "packages/b",
+    "c" => "packages/c",
+  },
+}
+`
+
 exports[`test/arborist/build-ideal-tree.js TAP add packages to workspaces, not root > tree with abbrev removed from a and b 1`] = `
 ArboristNode {
   "children": Map {

workspaces/arborist/test/arborist/build-ideal-tree.js

@@ -2674,6 +2674,19 @@ t.test('add packages to workspaces, not root', async t => {
   t.matchSnapshot(printTree(rmTree), 'tree with abbrev removed from a and b')
 })
 
+t.test('add one workspace to another', async t => {
+  const path = resolve(__dirname, '../fixtures/workspaces-not-root')
+  const packageA = resolve(path, 'packages/a')
+
+  const addTree = await buildIdeal(path, {
+    add: [packageA],
+    workspaces: ['c'],
+  })
+  const c = addTree.children.get('c').target
+  t.match(c.edgesOut.get('a'), { spec: 'file:../a' })
+  t.matchSnapshot(printTree(addTree), 'tree with workspace a added to workspace c')
+})
+
 t.test('workspace error handling', async t => {
   const path = t.testdir({
     'package.json': JSON.stringify({