From adc34f82e3725a53b4787fb8cf445635eb91f40c Mon Sep 17 00:00:00 2001
From: Christopher Dieringer <cdaringe@users.noreply.github.com>
Date: Thu, 13 Aug 2020 08:26:49 -0700
Subject: [PATCH] feat(core): add user-friendly error on invalid input

Prevent cryptic error of `TypeError: Cannot read property 'map' of undefined`, which doesn't guide the user towards success
---
 .../workspace/src/schematics/move/lib/update-imports.ts  | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/packages/workspace/src/schematics/move/lib/update-imports.ts b/packages/workspace/src/schematics/move/lib/update-imports.ts
index b1507c762c64e..9d2572af6a9ff 100644
--- a/packages/workspace/src/schematics/move/lib/update-imports.ts
+++ b/packages/workspace/src/schematics/move/lib/update-imports.ts
@@ -88,7 +88,14 @@ export function updateImports(schema: Schema) {
           const path = tsConfig.compilerOptions.paths[
             projectRef.from
           ] as string[];
-
+          if (!path) {
+            throw new Error(
+              [
+                `unable to find "${projectRef.from}" in`,
+                `${tsConfigPath} compilerOptions.paths`,
+              ].join(' ')
+            );
+          }
           const updatedPath = path.map((x) =>
             x.replace(new RegExp(projectRoot.from, 'g'), projectRoot.to)
           );