fix: update eresolve explanations for new arborist data provided

Fix: #3138

PR-URL: https://github.com/npm/cli/pull/3588
Credit: @isaacs
Close: #3588
Reviewed-by: @wraithgar

1 files changed, 11 insertions, 4 deletions

diff --git a/lib/utils/explain-eresolve.js b/lib/utils/explain-eresolve.js
index fa3c6bda5..b25e3e4a9 100644
--- a/lib/utils/explain-eresolve.js
+++ b/lib/utils/explain-eresolve.js
@@ -9,26 +9,33 @@ const { explainEdge, explainNode, printNode } = require('./explain-dep.js')
 // The full report (ie, depth=Infinity) is always written to the cache folder
 // at ${cache}/eresolve-report.txt along with full json.
 const explain = (expl, color, depth) => {
-  const { edge, current, peerConflict, currentEdge } = expl
+  const { edge, dep, current, peerConflict, currentEdge } = expl
 
   const out = []
-  if (edge.from && edge.from.whileInstalling)
-    out.push('While resolving: ' + printNode(edge.from.whileInstalling, color))
+  const whileInstalling = dep && dep.whileInstalling ||
+    current && current.whileInstalling ||
+    edge && edge.from && edge.from.whileInstalling
+  if (whileInstalling)
+    out.push('While resolving: ' + printNode(whileInstalling, color))
 
   // it "should" be impossible for an ERESOLVE explanation to lack both
   // current and currentEdge, but better to have a less helpful error
   // than a crashing failure.
   if (current)
     out.push('Found: ' + explainNode(current, depth, color))
+  else if (peerConflict && peerConflict.current)
+    out.push('Found: ' + explainNode(peerConflict.current, depth, color))
   else if (currentEdge)
     out.push('Found: ' + explainEdge(currentEdge, depth, color))
+  else /* istanbul ignore else - should always have one */ if (edge)
+    out.push('Found: ' + explainEdge(edge, depth, color))
 
   out.push('\nCould not resolve dependency:\n' +
     explainEdge(edge, depth, color))
 
   if (peerConflict) {
     const heading = '\nConflicting peer dependency:'
-    const pc = explainNode(peerConflict, depth, color)
+    const pc = explainNode(peerConflict.peer, depth, color)
     out.push(heading + ' ' + pc)
   }