1513527 - Switch from lodash to lodash-es

Status: RESOLVED WONTFIX

(Tree Management :: Treeherder: Frontend, enhancement, P3)

Description

[Ed Morley [:emorley]]

Since it allows webpack to tree shake unused modules, thereby saving us from including all of the parts of lodash we don't use in the bundle shipped to users.

Comment 1

[GitHub Bugzilla PR Linker]

Attachment: Link to GitHub pull-request: https://github.com/mozilla/treeherder/pull/4366

Comment 2

[Ed Morley [:emorley]]

The Travis run on the linked PR is failing - I believe due to quirks with karma-webpack which should go away once we migrate fully to Jest.

Comment 3

[Ed Morley [:emorley]]

No longer depends on bug 1364045 (finishing the migration from Karma to Jest), since I found an easy workaround for Karma.

However Jest's current lack of ESM (ES modules) causes test failures. Resolving would require either:

• telling Neutrino to make Babel transpile dependencies too (and not just our own code), which isn't ideal from a test-prod parity and perf point of view
• waiting for Jest's native ESM support: https://github.com/facebook/jest/issues/4842

The latter seems more appealing.

Also if lodash 5 ends up being released before that happens, then this bug can be wontfixed and the existing lodash package just updated to v5, which is due to use ES modules anyway.

Comment 4

[Ed Morley [:emorley]]

Let's not bother with this for now, seeing as lodash 5 will resolve the issue more easily.