dcc: refactor slider

.envrc

@@ -0,0 +1,8 @@
+# Check for common virtual environment directories from .gitignore patterns
+# and automatically activate one with direnv, if available.
+for venv_dir in .venv .env venv env .venv* env* ENV; do
+    if [ -d "$venv_dir" ] && [ -f "$venv_dir/bin/activate" ]; then
+        source "$venv_dir/bin/activate"
+        break
+    fi
+done

components/dash-core-components/jest.config.js

@@ -0,0 +1,17 @@
+module.exports = {
+  preset: 'ts-jest',
+  testEnvironment: 'node',
+  roots: ['<rootDir>/src'],
+  testMatch: ['**/__tests__/**/*.ts', '**/?(*.)+(spec|test).ts'],
+  transform: {
+    '^.+\\.ts$': 'ts-jest',
+  },
+  collectCoverageFrom: [
+    'src/**/*.{ts,tsx}',
+    '!src/**/*.d.ts',
+  ],
+  moduleNameMapper: {
+    '^@/(.*)$': '<rootDir>/src/$1',
+  },
+  setupFilesAfterEnv: ['<rootDir>/jest.setup.js'],
+};

components/dash-core-components/jest.setup.js

@@ -0,0 +1,2 @@
+// Jest setup file
+// This file is loaded before every test file