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Verification · Static analysis · Type checking

Strict mode

Disallow implicit any, untyped definitions and unchecked optional access.

How to build it

Set strict to true in tsconfig.json, or run mypy and pyright in strict mode.
Enable noImplicitAny and strictNullChecks, or disallow untyped definitions in mypy.
Fix the baseline errors and block new untyped or unchecked code in CI.

Signals in a repository

A tsconfig.json with "strict": true in compilerOptions.
A CI step running mypy --strict or a strict pyright configuration.

In practice

148 repositories run a tool for this check in the scanned set.

tsc · 117 repos
mypy · 35 repos
pyright · 16 repos

Examples

freeCodeCamp/freeCodeCamp · tsc
```
tsc -p tsconfig.build.json
```
nousresearch/hermes-agent · tsc
```
tsc --noEmit -p tsconfig.json
```
microsoft/vscode · tsc
```
tsc --project build/tsconfig.json
```
vercel/next.js · tsc
```
tsc
```

facebook/react-native · tsc

tsc -p packages/react-native/__typetests__/tsconfig.legacy.json