build: Use shared packages through modules

By running the build for the shared packages only once, errors in them
are reported only once in watch mode.

We still have to point jest to the original source files (and rebuild
the shared source files as part of the test), because it won't load the
"module" entry of the shared packages. However, as a benefit, jest can
now run even if the shared packages haven't been built yet.

1 files changed, 5 insertions, 0 deletions

diff --git a/jest.config.js b/jest.config.js
index 6943513..d0ba361 100644
--- a/jest.config.js
+++ b/jest.config.js
@@ -1,5 +1,7 @@
 // @ts-check
 
+const { join } = require('path');
+
 /** @type {import('ts-jest').InitialOptionsTsJest} */
 module.exports = {
   preset: 'ts-jest',
@@ -8,6 +10,9 @@ module.exports = {
       isolatedModules: true,
     },
   },
+  moduleNameMapper: {
+    '@sophie/(.+)': join(__dirname, 'packages/$1/src/index.ts'),
+  },
   resetMocks: true,
   restoreMocks: true,
   testEnvironment: 'node',