Install @babel/plugin-proposal-class-properties

package-lock.json

@@ -196,6 +196,42 @@
         "esutils": "^2.0.0"
       }
     },
+    "@babel/helper-create-class-features-plugin": {
+      "version": "7.4.4",
+      "resolved": "https://registry.npmjs.org/@babel/helper-create-class-features-plugin/-/helper-create-class-features-plugin-7.4.4.tgz",
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+      "dev": true,
+      "requires": {
+        "@babel/helper-function-name": "^7.1.0",
+        "@babel/helper-member-expression-to-functions": "^7.0.0",
+        "@babel/helper-optimise-call-expression": "^7.0.0",
+        "@babel/helper-plugin-utils": "^7.0.0",
+        "@babel/helper-replace-supers": "^7.4.4",
+        "@babel/helper-split-export-declaration": "^7.4.4"
+      },
+      "dependencies": {
+        "@babel/helper-split-export-declaration": {
+          "version": "7.4.4",
+          "resolved": "https://registry.npmjs.org/@babel/helper-split-export-declaration/-/helper-split-export-declaration-7.4.4.tgz",
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+          "dev": true,
+          "requires": {
+            "@babel/types": "^7.4.4"
+          }
+        },
+        "@babel/types": {
+          "version": "7.4.4",
+          "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.4.4.tgz",
+          "integrity": "sha512-dOllgYdnEFOebhkKCjzSVFqw/PmmB8pH6RGOWkY4GsboQNd47b1fBThBSwlHAq9alF9vc1M3+6oqR47R50L0tQ==",
+          "dev": true,
+          "requires": {
+            "esutils": "^2.0.2",
+            "lodash": "^4.17.11",
+            "to-fast-properties": "^2.0.0"
+          }
+        }
+      }
+    },
     "@babel/helper-function-name": {
       "version": "7.1.0",
       "resolved": "https://registry.npmjs.org/@babel/helper-function-name/-/helper-function-name-7.1.0.tgz",
@@ -216,12 +252,115 @@
         "@babel/types": "^7.0.0"
       }
     },
+    "@babel/helper-member-expression-to-functions": {
+      "version": "7.0.0",
+      "resolved": "https://registry.npmjs.org/@babel/helper-member-expression-to-functions/-/helper-member-expression-to-functions-7.0.0.tgz",
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+      "dev": true,
+      "requires": {
+        "@babel/types": "^7.0.0"
+      }
+    },
+    "@babel/helper-optimise-call-expression": {
+      "version": "7.0.0",
+      "resolved": "https://registry.npmjs.org/@babel/helper-optimise-call-expression/-/helper-optimise-call-expression-7.0.0.tgz",
+      "integrity": "sha512-u8nd9NQePYNQV8iPWu/pLLYBqZBa4ZaY1YWRFMuxrid94wKI1QNt67NEZ7GAe5Kc/0LLScbim05xZFWkAdrj9g==",
+      "dev": true,
+      "requires": {
+        "@babel/types": "^7.0.0"
+      }
+    },
     "@babel/helper-plugin-utils": {
       "version": "7.0.0",
       "resolved": "https://registry.npmjs.org/@babel/helper-plugin-utils/-/helper-plugin-utils-7.0.0.tgz",
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       "dev": true
     },
+    "@babel/helper-replace-supers": {
+      "version": "7.4.4",
+      "resolved": "https://registry.npmjs.org/@babel/helper-replace-supers/-/helper-replace-supers-7.4.4.tgz",
+      "integrity": "sha512-04xGEnd+s01nY1l15EuMS1rfKktNF+1CkKmHoErDppjAAZL+IUBZpzT748x262HF7fibaQPhbvWUl5HeSt1EXg==",
+      "dev": true,
+      "requires": {
+        "@babel/helper-member-expression-to-functions": "^7.0.0",
+        "@babel/helper-optimise-call-expression": "^7.0.0",
+        "@babel/traverse": "^7.4.4",
+        "@babel/types": "^7.4.4"
+      },
+      "dependencies": {
+        "@babel/generator": {
+          "version": "7.4.4",
+          "resolved": "https://registry.npmjs.org/@babel/generator/-/generator-7.4.4.tgz",
+          "integrity": "sha512-53UOLK6TVNqKxf7RUh8NE851EHRxOOeVXKbK2bivdb+iziMyk03Sr4eaE9OELCbyZAAafAKPDwF2TPUES5QbxQ==",
+          "dev": true,
+          "requires": {
+            "@babel/types": "^7.4.4",
+            "jsesc": "^2.5.1",
+            "lodash": "^4.17.11",
+            "source-map": "^0.5.0",
+            "trim-right": "^1.0.1"
+          }
+        },
+        "@babel/helper-split-export-declaration": {
+          "version": "7.4.4",
+          "resolved": "https://registry.npmjs.org/@babel/helper-split-export-declaration/-/helper-split-export-declaration-7.4.4.tgz",
+          "integrity": "sha512-Ro/XkzLf3JFITkW6b+hNxzZ1n5OQ80NvIUdmHspih1XAhtN3vPTuUFT4eQnela+2MaZ5ulH+iyP513KJrxbN7Q==",
+          "dev": true,
+          "requires": {
+            "@babel/types": "^7.4.4"
+          }
+        },
+        "@babel/parser": {
+          "version": "7.4.4",
+          "resolved": "https://registry.npmjs.org/@babel/parser/-/parser-7.4.4.tgz",
+          "integrity": "sha512-5pCS4mOsL+ANsFZGdvNLybx4wtqAZJ0MJjMHxvzI3bvIsz6sQvzW8XX92EYIkiPtIvcfG3Aj+Ir5VNyjnZhP7w==",
+          "dev": true
+        },
+        "@babel/traverse": {
+          "version": "7.4.4",
+          "resolved": "https://registry.npmjs.org/@babel/traverse/-/traverse-7.4.4.tgz",
+          "integrity": "sha512-Gw6qqkw/e6AGzlyj9KnkabJX7VcubqPtkUQVAwkc0wUMldr3A/hezNB3Rc5eIvId95iSGkGIOe5hh1kMKf951A==",
+          "dev": true,
+          "requires": {
+            "@babel/code-frame": "^7.0.0",
+            "@babel/generator": "^7.4.4",
+            "@babel/helper-function-name": "^7.1.0",
+            "@babel/helper-split-export-declaration": "^7.4.4",
+            "@babel/parser": "^7.4.4",
+            "@babel/types": "^7.4.4",
+            "debug": "^4.1.0",
+            "globals": "^11.1.0",
+            "lodash": "^4.17.11"
+          }
+        },
+        "@babel/types": {
+          "version": "7.4.4",
+          "resolved": "https://registry.npmjs.org/@babel/types/-/types-7.4.4.tgz",
+          "integrity": "sha512-dOllgYdnEFOebhkKCjzSVFqw/PmmB8pH6RGOWkY4GsboQNd47b1fBThBSwlHAq9alF9vc1M3+6oqR47R50L0tQ==",
+          "dev": true,
+          "requires": {
+            "esutils": "^2.0.2",
+            "lodash": "^4.17.11",
+            "to-fast-properties": "^2.0.0"
+          }
+        },
+        "debug": {
+          "version": "4.1.1",
+          "resolved": "https://registry.npmjs.org/debug/-/debug-4.1.1.tgz",
+          "integrity": "sha512-pYAIzeRo8J6KPEaJ0VWOh5Pzkbw/RetuzehGM7QRRX5he4fPHx2rdKMB256ehJCkX+XRQm16eZLqLNS8RSZXZw==",
+          "dev": true,
+          "requires": {
+            "ms": "^2.1.1"
+          }
+        },
+        "ms": {
+          "version": "2.1.1",
+          "resolved": "https://registry.npmjs.org/ms/-/ms-2.1.1.tgz",
+          "integrity": "sha512-tgp+dl5cGk28utYktBsrFqA7HKgrhgPsg6Z/EfhWI4gl1Hwq8B/GmY/0oXZ6nF8hDVesS/FpnYaD/kOWhYQvyg==",
+          "dev": true
+        }
+      }
+    },
     "@babel/helper-split-export-declaration": {
       "version": "7.0.0",
       "resolved": "https://registry.npmjs.org/@babel/helper-split-export-declaration/-/helper-split-export-declaration-7.0.0.tgz",
@@ -386,6 +525,16 @@
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       "dev": true
     },
+    "@babel/plugin-proposal-class-properties": {
+      "version": "7.4.4",
+      "resolved": "https://registry.npmjs.org/@babel/plugin-proposal-class-properties/-/plugin-proposal-class-properties-7.4.4.tgz",
+      "integrity": "sha512-WjKTI8g8d5w1Bc9zgwSz2nfrsNQsXcCf9J9cdCvrJV6RF56yztwm4TmJC0MgJ9tvwO9gUA/mcYe89bLdGfiXFg==",
+      "dev": true,
+      "requires": {
+        "@babel/helper-create-class-features-plugin": "^7.4.4",
+        "@babel/helper-plugin-utils": "^7.0.0"
+      }
+    },
     "@babel/plugin-syntax-jsx": {
       "version": "7.2.0",
       "resolved": "https://registry.npmjs.org/@babel/plugin-syntax-jsx/-/plugin-syntax-jsx-7.2.0.tgz",

package.json

@@ -22,6 +22,7 @@
   "devDependencies": {
     "@babel/cli": "^7.4.4",
     "@babel/core": "^7.4.4",
+    "@babel/plugin-proposal-class-properties": "^7.4.4",
     "@babel/preset-react": "^7.0.0",
     "@babel/preset-typescript": "^7.3.3",
     "@types/prop-types": "^15.7.1",