jaredpalmer/formik

Array-helper `insert` adds value to error state

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#1092 opened on Nov 8, 2018

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 (5 comments) (3 reactions) (0 assignees)TypeScript (34,255 stars) (2,801 forks)batch import
Priority: MediumType: Bughelp wantedpinned

Description

🐛 Bug report

Current Behavior

When i add an item to a FieldArray using insert the value is also inserted into the errors state (see example below).

Expected behavior

Only insert the value to the values state, not to the errors state.

Reproducible example

https://codesandbox.io/s/v87n4p6023

Your environment

Software Version(s)
Formik 1.3.1
React 16.5.2

Contributor guide

Tech stack
typescriptreact
Domain
frontend
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
2
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
under 1 hour
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
mostly clear
Prerequisites
Basic knowledge of ReactFamiliarity with Formik's FieldArray
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70
Research direction
The bug is that the `insert` method in Formik's FieldArray incorrectly adds the value to the errors state. Start by examining the `insert` function in `packages/formik/src/FieldArray.tsx`. Look at how it updates both values and errors; it likely uses `setIn` or similar helpers. The fix should ensure `insert` only updates values, not errors. The provided CodeSandbox (https://codesandbox.io/s/v87n4p6023) reproduces the issue. Check the existing comments for any additional clues or attempted fixes.