fix: add jest coverage config to package.json (#3896)

* fix: add jest coverage config to package.json

* fix: add running test instructions to CONTRIBUTING.md

* fix: respond to zzmp comments

* fix: lower test thresholds
Co-authored-by: Lynn Yu <lynn.yu@uniswap.org>

CONTRIBUTING.md

-
 # Contributing
 
 Thank you for your interest in contributing to the Uniswap interface! 🦄
@@ -15,6 +14,16 @@ Thank you for your interest in contributing to the Uniswap interface! 🦄
 1. `yarn install`
 1. `yarn build`
 
+## Running unit tests
+
+- Run unit tests: `yarn test`
+- Run unit tests and show test coverage info for all tests: `yarn test --watchAll`
+
+## Running cypress integration tests
+
+1. `yarn build:e2e`
+2. `yarn test:e2e`
+
 ## Engineering standards
 
 Code merged into the `main` branch of this repository should adhere to high standards of correctness and maintainability.

package.json

@@ -16,11 +16,32 @@
     "prepare": "yarn contracts:compile && yarn graphql:generate && yarn i18n:compile",
     "start": "react-scripts start",
     "build": "react-scripts build",
-    "test": "react-scripts test",
+    "test": "react-scripts test --coverage",
     "build:e2e": "env-cmd -f .env yarn build",
     "test:e2e": "start-server-and-test 'serve build -l 3000' http://localhost:3000 'cypress open'",
     "test:e2e:ci": "start-server-and-test 'serve build -l 3000' http://localhost:3000 'cypress run --record'"
   },
+  "jest": {
+    "collectCoverageFrom": 
+    [
+      "src/components/**/*.ts*", 
+      "src/hooks/**/*.ts*", 
+      "src/lib/hooks/**/*.ts*", 
+      "src/lib/state/**/*.ts*", 
+      "src/lib/utils/**/*.ts*", 
+      "src/pages/**/*.ts*",
+      "src/state/**/*.ts*",
+      "src/utils/**/*.ts*"
+    ],
+    "coverageThreshold": {
+      "global": {
+        "branches": 4,
+        "functions": 6,
+        "lines": 9,
+        "statements": 9
+      }
+    }
+  },
   "browserslist": {
     "production": [
       ">0.2%",