Add Flow type definitions (#260)

test/_flow.js

@@ -0,0 +1,94 @@
+// @flow
+import chalk from '..';
+
+// $ExpectError (Can't have typo in option name)
+chalk.constructor({levl: 1});
+chalk.constructor({level: 1});
+
+// $ExpectError (Option must have proper type)
+new chalk.constructor({enabled: 'true'});
+new chalk.constructor({enabled: true});
+
+// $ExpectError (Can't pass in null)
+chalk.underline(null);
+chalk.underline('foo');
+
+// $ExpectError (Can't have typo in chalk method)
+chalk.rd('foo');
+chalk.red('foo');
+
+// $ExpectError (Can't have typo in chalk method)
+chalk.gren`foo`;
+chalk.green`foo`;
+
+// $ExpectError (Can't have typo in chalk method)
+chalk.red.bgBlu.underline('foo');
+chalk.red.bgBlue.underline('foo');
+
+// $ExpectError (Level must be 0, 1, 2, or 3)
+const badCtx = chalk.constructor({level: 4});
+const ctx = chalk.constructor({level: 3});
+
+// $ExpectError (Can't pass in null)
+ctx(null);
+ctx('foo');
+
+// $ExpectError (Can't have typo in method name)
+ctx.gry('foo');
+ctx.grey('foo');
+
+// $ExpectError (Can't have typo in method name)
+ctx`foo`.value();
+ctx`foo`.valueOf();
+
+// $ExpectError (Can't have typo in property name)
+chalk.abled = true;
+chalk.enabled = true;
+
+// $ExpectError (Can't use invalid Level for property setter)
+chalk.level = 10;
+chalk.level = 1;
+
+const chalkInstance = new chalk.constructor();
+
+// $ExpectError (Can't have typo in method name)
+chalkInstance.blu('foo');
+chalkInstance.blue('foo');
+chalkInstance`foo`;
+
+// $ExpectError (Can't have typo in method name)
+chalk.keywrd('orange').bgBlue('foo');
+chalk.keyword('orange').bgBlue('foo');
+
+// $ExpectError (rgb should take in 3 numbers)
+chalk.rgb(1, 14).bgBlue('foo');
+chalk.rgb(1, 14, 9).bgBlue('foo');
+
+// $ExpectError (hsl should take in 3 numbers)
+chalk.hsl(1, 14, '9').bgBlue('foo');
+chalk.hsl(1, 14, 9).bgBlue('foo');
+
+// $ExpectError (hsv should take in 3 numbers)
+chalk.hsv(1, 14).bgBlue('foo');
+chalk.hsv(1, 14, 9).bgBlue('foo');
+
+// $ExpectError (hwb should take in 3 numbers)
+chalk.hwb(1, 14).bgBlue('foo');
+chalk.hwb(1, 14, 9).bgBlue('foo');
+
+// $ExpectError (Can't have typo in method name)
+chalk.visibl('foo');
+chalk.visible('foo');
+
+// $ExpectError (Can't have typo in method name)
+chalk.red.visibl('foo');
+chalk.red.visible('foo');
+chalk.visible.red('foo');
+
+// $ExpectError (Can't write to readonly property)
+chalk.black = 'foo';
+chalk.black;
+
+// $ExpectError (Can't write to readonly property)
+chalk.reset = 'foo';
+console.log(chalk.reset);