Change the type of the attr function so it returns Maybe instead of

breaking with a javascript error when there are no selected elements.
This commit is contained in:
Gareth Daniel Smith 2018-07-29 14:31:38 +01:00
parent 57983d156d
commit 4145c4634c
4 changed files with 38 additions and 14 deletions

View File

@ -1,8 +1,8 @@
const cheerio = require('cheerio')
// Attributes
exports.attrImpl = function(name, cheerioInst) {
return cheerioInst.attr(name);
exports.attrImpl = function(nothing, just, name, cheerioInst) {
return cheerioInst.length ? just(cheerioInst.attr(name)) : nothing;
}
exports.hasClassImpl = function(className, cheerioInst) {
@ -48,8 +48,7 @@ exports.eqImpl = function(index, cheerioInst) {
// Rendering
exports.htmlImpl = function(nothing, just, cheerioInst) {
const ret = cheerioInst.html()
return ret != null ? just(ret) : nothing
return cheerioInst.length ? just(cheerioInst.html()) : nothing;
}
exports.text = function(cheerioInst) {
@ -59,4 +58,4 @@ exports.text = function(cheerioInst) {
// Miscellaneous
exports.length = function(cheerioInst) {
return cheerioInst.length;
}
}

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@ -1,15 +1,18 @@
module Cheerio where
import Data.Function.Uncurried (Fn2, Fn3, runFn2, runFn3)
import Data.Function.Uncurried (Fn2, Fn3, Fn4, runFn2, runFn3, runFn4)
import Data.Maybe (Maybe(..))
foreign import data Cheerio :: Type
-- Attributes
foreign import attrImpl :: Fn2 String Cheerio String
foreign import attrImpl :: forall a.
Fn4 (Maybe a) (a -> Maybe a) String Cheerio (Maybe String)
attr :: String -> Cheerio -> String
attr = runFn2 attrImpl
-- | Gets an attribute value from the first selected element, returning
-- | Nothing when there are no selected elements.
attr :: String -> Cheerio -> Maybe String
attr = runFn4 attrImpl Nothing Just
foreign import hasClassImpl :: Fn2 String Cheerio Boolean
@ -39,10 +42,12 @@ eq = runFn2 eqImpl
foreign import htmlImpl :: forall a.
Fn3 (Maybe a) (a -> Maybe a) Cheerio (Maybe String)
-- | Gets an html content string from the first selected element, returning
-- | Nothing when there are no selected elements.
html :: Cheerio -> Maybe String
html = runFn3 htmlImpl Nothing Just
foreign import text :: Cheerio -> String
-- Miscellaneous
foreign import length :: Cheerio -> Int
foreign import length :: Cheerio -> Int

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@ -9,7 +9,8 @@ import Test.Unit.Assert as Assert
import Test.Unit.Main (runTest)
import Cheerio
( attr
( Cheerio
, attr
, children
, eq
, find
@ -32,14 +33,21 @@ import Test.HtmlEx (htmlEx)
main :: Effect Unit
main = runTest suites
emptyCheerio :: Cheerio
emptyCheerio = loadRoot htmlEx # find ".no-such-element"
suites :: TestSuite
suites = do
suite "Attributes" do
test "attr" do
Assert.equal
"fruits"
(Just "fruits")
(loadRoot htmlEx # find "ul" # attr "id")
Assert.equal
Nothing
(emptyCheerio # attr "id")
test "hasClass" do
Assert.equal
true
@ -53,6 +61,10 @@ suites = do
true
(loadRoot htmlEx # find "li" # hasClass "pear")
Assert.equal
false
(emptyCheerio # hasClass "pear")
suite "Traversing" do
test "find" do
Assert.equal
@ -61,7 +73,7 @@ suites = do
test "parent" do
Assert.equal
"fruits"
(Just "fruits")
(loadRoot htmlEx # find ".pear" # parent # attr "id")
test "next" do
@ -109,11 +121,19 @@ suites = do
(Just "Apple")
(loadRoot htmlEx # find ".apple" # html)
Assert.equal
Nothing
(emptyCheerio # html)
test "text" do
Assert.equal
"Apple"
(loadRoot htmlEx # find ".apple" # text)
Assert.equal
""
(emptyCheerio # text)
suite "More" do
test "Long chain" do
Assert.equal

View File

@ -35,7 +35,7 @@ suites = do
suite "Selectors" do
test "select" do
Assert.equal
"pear"
(Just "pear")
(load htmlEx # select "ul .pear" # attr "class")
test "selectDeep" do