Merge branch 'master' into breaking/const-fixes

evilsoft · Oct 27, 2018 · 75da592 · 75da592
2 parents f8fb5da + f7641f3
commit 75da592
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Showing 4 changed files with 17 additions and 5 deletions.
diff --git a/docs/src/pages/docs/functions/helpers.md b/docs/src/pages/docs/functions/helpers.md
@@ -1000,7 +1000,7 @@ exercise some discipline here to not mutate.
 `crocks/Result/tryCatch`
 
 ```haskell
-tryCatch :: (a -> b) -> a -> Result e b
+tryCatch :: ((*) -> b) -> (*) -> Result e b
 ```
 
 Typical try-catch blocks are very imperative in their usage. This `tryCatch`

diff --git a/docs/src/pages/docs/functions/index.md b/docs/src/pages/docs/functions/index.md
@@ -99,7 +99,7 @@ need to account for for the rest of your flow.
 | [`setPath`][setpath] | <code>[ String &#124; Integer ] -> a -> (Object &#124; Array) -> (Object &#124; Array)</code> | `crocks/helpers/setPath` |
 | [`tap`][tap] | `(a -> b) -> a -> a` | `crocks/helpers/tap` |
 | [`toPairs`][topairs] | `Object -> List (Pair String a)` | `crocks/Pair/toPairs` |
-| [`tryCatch`][trycatch] | `(a -> b) -> a -> Result e b` | `crocks/Result/tryCatch` |
+| [`tryCatch`][trycatch] | `((*) -> b) -> (*) -> Result e b` | `crocks/Result/tryCatch` |
 | [`unary`][unary] | `((*) -> b) -> a -> b` | `crocks/helpers/unary` |
 | [`unit`][unit] | `() -> undefined` | `crocks/helpers/unit` |
 | [`unsetPath`][unsetpath] |  <code>[ String &#124; Integer] -> (Object &#124; Array) -> (Object &#124; Array)</code>  | `crocks/helpers/unsetPath` |

diff --git a/src/Result/tryCatch.js b/src/Result/tryCatch.js
@@ -10,10 +10,14 @@ function tryCatch(fn) {
     throw new TypeError('tryCatch: Function required for first argument')
   }
 
-  return function(x) {
-    try { return Ok(fn(x)) }
+  const safe = function() {
+    try { return Ok(fn.apply(this, arguments)) }
     catch(e) { return Err(e) }
   }
+
+  Object.defineProperty(safe, 'length', { value: fn.length })
+
+  return safe
 }
 
 module.exports = curry(tryCatch)
diff --git a/src/Result/tryCatch.spec.js b/src/Result/tryCatch.spec.js
@@ -5,6 +5,7 @@ const bindFunc = helpers.bindFunc
 
 const Result = require('.')
 const isFunction = require('../core/isFunction')
+const equals = require('../core/equals')
 const isSameType = require('../core/isSameType')
 const unit = require('../core/_unit')
 
@@ -43,7 +44,6 @@ test('tryCatch functionality', t => {
 
   const f = x => x
   const g = () =>  { throw new Error(msg) }
-
   const extract =
     either(identity, constant('Ok'))
 
@@ -59,5 +59,13 @@ test('tryCatch functionality', t => {
   t.equals(good, 'Ok', 'returns an Ok when no error')
   t.equals(bad.message, msg, 'returns an Err with error on error')
 
+  const x = (a, b, c) => ({ a, b, c })
+
+  const noncurried = tryCatch(x, 1,2,3).either(identity, identity)
+  const curried = tryCatch(x, 1)(2)(3).either(identity, identity)
+
+  t.equals(equals(noncurried, { a: 1, b: 2, c: 3 }), true, 'preserves the arity of the passed function')
+  t.equals(equals(curried, { a: 1, b: 2, c: 3 }), true, 'returned function is curried')
+
   t.end()
 })