add code formatting linting (gnosis/gp-v2-contracts#54)

This PR adds code formatting linting to the project.

### Test Plan

CI

.prettierrc.js

@@ -1,3 +1,12 @@
 module.exports = {
+  bracketSpacing: true,
   trailingComma: "all",
+  overrides: [
+    {
+      files: "*.sol",
+      options: {
+        bracketSpacing: false,
+      },
+    },
+  ],
 };

.solhint.json

@@ -1,6 +1,8 @@
 {
   "extends": "solhint:recommended",
+  "plugins": ["prettier"],
   "rules": {
-    "compiler-version": ["error", "^0.6.12"]
+    "compiler-version": ["error", "^0.6.12"],
+    "prettier/prettier": "error"
   }
 }

package.json

@@ -28,7 +28,9 @@
     "ethereum-waffle": "^3.1.1",
     "ethers": "^5.0.14",
     "prettier": "^2.1.2",
+    "prettier-plugin-solidity": "^1.0.0-alpha.58",
     "solhint": "^3.2.1",
+    "solhint-plugin-prettier": "^0.0.5",
     "ts-node": "^9.0.0",
     "typescript": "^4.0.3"
   }

yarn.lock

@@ -3043,6 +3043,11 @@ dir-glob@^3.0.1:
   dependencies:
     path-type "^4.0.0"
 
+dir-to-object@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/dir-to-object/-/dir-to-object-2.0.0.tgz#29723e9bd1c3e58e4f307bd04ff634c0370c8f8a"
+  integrity sha512-sXs0JKIhymON7T1UZuO2Ud6VTNAx/VTBXIl4+3mjb2RgfOpt+hectX0x04YqPOPdkeOAKoJuKqwqnXXURNPNEA==
+
 [email protected]:
   version "1.5.0"
   resolved "https://registry.yarnpkg.com/doctrine/-/doctrine-1.5.0.tgz#379dce730f6166f76cefa4e6707a159b02c5a6fa"
@@ -3166,6 +3171,16 @@ emoji-regex@^7.0.1:
   resolved "https://registry.yarnpkg.com/emoji-regex/-/emoji-regex-7.0.3.tgz#933a04052860c85e83c122479c4748a8e4c72156"
   integrity sha512-CwBLREIQ7LvYFB0WyRvwhq5N5qPhc6PMjD6bYggFlI5YyDgl+0vxq5VHbMOFqLg7hfWzmu8T5Z1QofhmTIhItA==
 
+emoji-regex@^8.0.0:
+  version "8.0.0"
+  resolved "https://registry.yarnpkg.com/emoji-regex/-/emoji-regex-8.0.0.tgz#e818fd69ce5ccfcb404594f842963bf53164cc37"
+  integrity sha512-MSjYzcWNOA0ewAHpz0MxpYFvwg6yjy1NG3xteoqz644VCo/RPgnr1/GGt+ic3iJTzQ8Eu3TdM14SawnVUmGE6A==
+
+emoji-regex@^9.0.0:
+  version "9.0.0"
+  resolved "https://registry.yarnpkg.com/emoji-regex/-/emoji-regex-9.0.0.tgz#48a2309cc8a1d2e9d23bc6a67c39b63032e76ea4"
+  integrity sha512-6p1NII1Vm62wni/VR/cUMauVQoxmLVb9csqQlvLz+hO2gk8U2UYDfXHQSUYIBKmZwAKz867IDqG7B+u0mj+M6w==
+
 encodeurl@~1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/encodeurl/-/encodeurl-1.0.2.tgz#ad3ff4c86ec2d029322f5a02c3a9a606c95b3f59"
@@ -3312,6 +3327,11 @@ [email protected], escape-string-regexp@^1.0.2, escape-string-regexp@^1
   resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-1.0.5.tgz#1b61c0562190a8dff6ae3bb2cf0200ca130b86d4"
   integrity sha1-G2HAViGQqN/2rjuyzwIAyhMLhtQ=
 
+escape-string-regexp@^4.0.0:
+  version "4.0.0"
+  resolved "https://registry.yarnpkg.com/escape-string-regexp/-/escape-string-regexp-4.0.0.tgz#14ba83a5d373e3d311e5afca29cf5bfad965bf34"
+  integrity sha512-TtpcNJ3XAzx3Gq8sWRzJaVajRs0uVxA2YAkdb1jm2YkPz4G6egUFAyA3n5vtEIZefPk5Wa4UXbKuS5fKkJWdgA==
+
 eslint-config-prettier@^6.12.0:
   version "6.12.0"
   resolved "https://registry.yarnpkg.com/eslint-config-prettier/-/eslint-config-prettier-6.12.0.tgz#9eb2bccff727db1c52104f0b49e87ea46605a0d2"
@@ -3509,6 +3529,13 @@ espree@^7.3.0:
     acorn-jsx "^5.2.0"
     eslint-visitor-keys "^1.3.0"
 
+esprima-extract-comments@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/esprima-extract-comments/-/esprima-extract-comments-1.1.0.tgz#0dacab567a5900240de6d344cf18c33617becbc9"
+  integrity sha512-sBQUnvJwpeE9QnPrxh7dpI/dp67erYG4WXEAreAMoelPRpMR7NWb4YtwRPn9b+H1uLQKl/qS8WYmyaljTpjIsw==
+  dependencies:
+    esprima "^4.0.0"
+
 esprima@^4.0.0:
   version "4.0.1"
   resolved "https://registry.yarnpkg.com/esprima/-/esprima-4.0.1.tgz#13b04cdb3e6c5d19df91ab6987a8695619b0aa71"
@@ -4183,6 +4210,14 @@ extglob@^2.0.4:
     snapdragon "^0.8.1"
     to-regex "^3.0.1"
 
+extract-comments@^1.1.0:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/extract-comments/-/extract-comments-1.1.0.tgz#b90bca033a056bd69b8ba1c6b6b120fc2ee95c18"
+  integrity sha512-dzbZV2AdSSVW/4E7Ti5hZdHWbA+Z80RJsJhr5uiL10oyjl/gy7/o+HI1HwK4/WSZhlq4SNKU3oUzXlM13Qx02Q==
+  dependencies:
+    esprima-extract-comments "^1.1.0"
+    parse-code-context "^1.0.0"
+
 [email protected]:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/extsprintf/-/extsprintf-1.3.0.tgz#96918440e3041a7a414f8c52e3c574eb3c3e1e05"
@@ -5468,6 +5503,11 @@ is-fullwidth-code-point@^2.0.0:
   resolved "https://registry.yarnpkg.com/is-fullwidth-code-point/-/is-fullwidth-code-point-2.0.0.tgz#a3b30a5c4f199183167aaab93beefae3ddfb654f"
   integrity sha1-o7MKXE8ZkYMWeqq5O+764937ZU8=
 
+is-fullwidth-code-point@^3.0.0:
+  version "3.0.0"
+  resolved "https://registry.yarnpkg.com/is-fullwidth-code-point/-/is-fullwidth-code-point-3.0.0.tgz#f116f8064fe90b3f7844a38997c0b75051269f1d"
+  integrity sha512-zymm5+u+sCsSWyD9qNaejV3DFvhCKclKdizYaJUuHA83RLjb7nSuGnddCHGv0hk+KY7BMAlsWeK4Ueg6EV6XQg==
+
 is-function@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/is-function/-/is-function-1.0.2.tgz#4f097f30abf6efadac9833b17ca5dc03f8144e08"
@@ -6992,6 +7032,11 @@ parse-asn1@^5.0.0, parse-asn1@^5.1.5:
     pbkdf2 "^3.0.3"
     safe-buffer "^5.1.1"
 
+parse-code-context@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/parse-code-context/-/parse-code-context-1.0.0.tgz#718c295c593d0d19a37f898473268cc75e98de1e"
+  integrity sha512-OZQaqKaQnR21iqhlnPfVisFjBWjhnMl5J9MgbP8xC+EwoVqbXrq78lp+9Zb3ahmLzrIX5Us/qbvBnaS3hkH6OA==
+
 parse-filepath@^1.0.1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/parse-filepath/-/parse-filepath-1.0.2.tgz#a632127f53aaf3d15876f5872f3ffac763d6c891"
@@ -7246,12 +7291,26 @@ prettier-linter-helpers@^1.0.0:
   dependencies:
     fast-diff "^1.1.2"
 
+prettier-plugin-solidity@^1.0.0-alpha.58:
+  version "1.0.0-alpha.58"
+  resolved "https://registry.yarnpkg.com/prettier-plugin-solidity/-/prettier-plugin-solidity-1.0.0-alpha.58.tgz#87e44b21bd9bd6ad4b28b1ac62ccdce59fb82fe3"
+  integrity sha512-G2xj98uEtfTcSc4qZcQ+MLwibpDNhBmOJk9ezTJ7uQLtTMGP1X9PqRnRlJW/vxbStPw/TVvnYD5rXwd1KZbTsg==
+  dependencies:
+    "@solidity-parser/parser" "^0.8.1"
+    dir-to-object "^2.0.0"
+    emoji-regex "^9.0.0"
+    escape-string-regexp "^4.0.0"
+    extract-comments "^1.1.0"
+    prettier "^2.0.5"
+    semver "^7.3.2"
+    string-width "^4.2.0"
+
 prettier@^1.14.3:
   version "1.19.1"
   resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.19.1.tgz#f7d7f5ff8a9cd872a7be4ca142095956a60797cb"
   integrity sha512-s7PoyDv/II1ObgQunCbB9PdLmUcBZcnWOcxDh7O0N/UwDEsHyqkW+Qh28jW+mVuCdx7gLB0BotYI1Y6uI9iyew==
 
-prettier@^2.1.2:
+prettier@^2.0.5, prettier@^2.1.2:
   version "2.1.2"
   resolved "https://registry.yarnpkg.com/prettier/-/prettier-2.1.2.tgz#3050700dae2e4c8b67c4c3f666cdb8af405e1ce5"
   integrity sha512-16c7K+x4qVlJg9rEbXl7HEGmQyZlG4R9AgP+oHKRMsMsuk8s+ATStlf1NpDqyBI1HpVyfjLOeMhH2LvuNvV5Vg==
@@ -8235,6 +8294,13 @@ solc@^0.6.3:
     semver "^5.5.0"
     tmp "0.0.33"
 
+solhint-plugin-prettier@^0.0.5:
+  version "0.0.5"
+  resolved "https://registry.yarnpkg.com/solhint-plugin-prettier/-/solhint-plugin-prettier-0.0.5.tgz#e3b22800ba435cd640a9eca805a7f8bc3e3e6a6b"
+  integrity sha512-7jmWcnVshIrO2FFinIvDQmhQpfpS2rRRn3RejiYgnjIE68xO2bvrYvjqVNfrio4xH9ghOqn83tKuTzLjEbmGIA==
+  dependencies:
+    prettier-linter-helpers "^1.0.0"
+
 solhint@^3.2.1:
   version "3.2.1"
   resolved "https://registry.yarnpkg.com/solhint/-/solhint-3.2.1.tgz#62f250930fe2fdaf8787e50ad35c038eedb52bbf"
@@ -8452,6 +8518,15 @@ string-width@^3.0.0, string-width@^3.1.0:
     is-fullwidth-code-point "^2.0.0"
     strip-ansi "^5.1.0"
 
+string-width@^4.2.0:
+  version "4.2.0"
+  resolved "https://registry.yarnpkg.com/string-width/-/string-width-4.2.0.tgz#952182c46cc7b2c313d1596e623992bd163b72b5"
+  integrity sha512-zUz5JD+tgqtuDjMhwIg5uFVV3dtqZ9yQJlZVfq4I01/K5Paj5UHj7VyrQOJvzawSVlKpObApbfD0Ed6yJc+1eg==
+  dependencies:
+    emoji-regex "^8.0.0"
+    is-fullwidth-code-point "^3.0.0"
+    strip-ansi "^6.0.0"
+
 string.prototype.trim@~1.2.1:
   version "1.2.2"
   resolved "https://registry.yarnpkg.com/string.prototype.trim/-/string.prototype.trim-1.2.2.tgz#f538d0bacd98fc4297f0bef645226d5aaebf59f3"