| 75 | | |
| 76 | | ''Ross:'' I think we had a successful contributing with standards and trying to be as conformant as possible. |
| 77 | | |
| 78 | | ''Ross:'' We have had a more balanced participation in Source/JavaScriptCore in 2019-2020 in the last year. In the last year more contributions have been done by non-apple contributors. Slack has been great for our communication on the JSC part of the project. There’s also a biweekly OSS staff meeting. |
| 79 | | |
| 80 | | ''Ross:'' The rest of the presentation is focused on standards-related work in the JSC team. |
| 81 | | |
| 82 | | ''Ross:'' But there are cases where we use our knowledge and work in JSC to help contribute to standards work. |
| 83 | | |
| 84 | | ''Alexey:'' Today we have an all time high on test262 (JS spec test suite) |
| 85 | | |
| 86 | | ''Alexey:'' Overall we have an 85% pass rate up from 80% in 2019 |
| 87 | | |
| 88 | | ''Alexey:'' There have been a number of notable fixes in the last year. Keith (me) fixei unescaped astral literals in indentifiers. Saam fixed Array.prototype to work with indicies beyond 2^32 |
| 89 | | |
| 90 | | ''Alexey:'' ProxyObject has been improved such as trap failures, relection, in the prototype chain, etc. |
| 91 | | |
| 92 | | ''Alexey:'' Early errors for unicode RegExps |
| 93 | | |
| 94 | | ''Alexey:'' [[DefineOwnProperty]] no longer corrupts property name order (for-in) |
| 95 | | |
| 96 | | ''Alexey:'' Classes no longer rely on `_proto_ ops handle [[IsHTMLDDA]] correctly |
| 97 | | |
| 98 | | ''Alexey:'' Array.prototype.sort was aligned with the new tightened spec. |
| 99 | | |
| 100 | | ''Alexey:'' Ross aligned TypedArray internal and prototype methods with the spec (while at the same time fixing the spec) |
| 101 | | |
| 102 | | ''Caio:'' Public and private fields are currently a stage 3 proposal in TC-39 |
| 103 | | |
| 104 | | ''Caio:'' In the last year Safari shipped with public fields |
| 105 | | |
| 106 | | ''Caio:'' With fields the constructor of a class will install each of the fields in the class onto the object it creates |
| 107 | | |
| 108 | | ''Caio:'' Private fields are a bit different because the identifier is only accessible from inside the lexical scope of the class definition |
| 109 | | |
| 110 | | ''Caio:'' Igalia has been working on this and has also been working on other class features. |
| 111 | | |
| 112 | | ''Ross:'' Were you also gonig to tell us about BigInt? |
| 113 | | |
| 114 | | ''Caio:'' Robin and I have been working on BigInt over the last year |
| 115 | | |
| 116 | | ''Caio:'' BigInts are similar to numbers in JS but they have infinite precision. i.e. when you go over 2^53 with BigInt you will not lose precision. |
| 117 | | |
| 118 | | ''Ross:'' New 262 features. |
| 119 | | |
| 120 | | ''Yusuke:'' WeakRef and FinalizationRegistry, implemented by Keith (me) |
| 121 | | |
| 122 | | ''Yususke:'' With WeakRef, it’s now possible to create a weak map where the values are held weakly |
| 123 | | |
| 124 | | ''Yusuke:'' In fact we are already using WeakRef in the WebInspector |
| 125 | | |
| 126 | | ''Ross:'' Short-circuiting assignment operators. |
| 127 | | |
| 128 | | ''Ross:'' This proposal was delayed until the nullish coalesing feature has been shipped. |
| 129 | | |
| 130 | | ''Ross:'' short ciruiting assignment was implemented by Devin |
| 131 | | |
| 132 | | ''Ross:'' String.prototype.replaceAll does what you would have expected replace all along. |
| 133 | | |
| 134 | | ''Ross:'' Previously if you didn’t use the global flag on a regexp or used a string regexp replace would only replace the first occurrance |
| 135 | | |
| 136 | | ''Ross:'' Array.prototype.at (originally, proposed as Array.prototype.item) |
| 137 | | |
| 138 | | ''Ross:'' has an advantage for access because it works with negative indicies |
| 139 | | |
| 140 | | ''Yusuke:'' Intl |
| 141 | | |
| 142 | | ''Yusuke:'' We went from 37% conformance to 98% conformance |
| 143 | | |
| 144 | | ''Yusuke:'' Ross and I worked closely on getting everything working |
| 145 | | |
| 146 | | Included work with ICU, perf, and new feature work. |
| 147 | | |
| 148 | | ''Yusuke:'' * describes all the new Intl features we have shipped * |
| 149 | | |
| 150 | | ''Yusuke:'' New Webassembly features this year are mutable Globals |
| 151 | | |
| 152 | | ''Ross:'' Looking ahead to 2021 we want to get to 90% pass rate on test262 |
| 153 | | |
| 154 | | The important part here isn’t just to get 90% but rather that we want to establish 90% as our new baseline and continually improve on that |
| 155 | | |
| 156 | | ''Caio:'' We also want to continue our class properties work to implement private methods |
| 157 | | |
| 158 | | ''Caio:'' Not limited to just functions but also can include private getters and setters |
| 159 | | |
| 160 | | ''Caio:'' Last but not least we also want to add static class fields and static private methods |
| 161 | | |
| 162 | | ''Yusuke:'' We have also re-enabled SharedArrayBuffer and Atomics in the build and in testers\ |
| 163 | | |
| 164 | | ''Yusuke:'' We also want to add Top-level await. This lets us put the await expression at the top level of module code. |
| 165 | | |
| 166 | | ''Yusuke:'' Another module feature we want is to have modules in workers |
| 167 | | |
| 168 | | ''Yusuke:'' And many more features all coming soon! |
| 169 | | |
| 170 | | ''Yusuke:'' We also hope to have more collaboration and build on the progress we have made this year |
| 171 | | |
| 172 | | ''Jen:'' Questions? |
| 173 | | |
| 174 | | ''Saam:'' Where are we at in test262 conformance again? |
| 175 | | |
| 176 | | ''Ross:'' Roughly we are at 85% |
| 177 | | |
| 178 | | ''Ryosuke:'' Is private class fields enabled in safari 14 |
| 179 | | |
| 180 | | ''Yusuke:'' Private fields just landed a few minutes ago so no |
| 181 | | |
| 182 | | ''Ryosuke:'' I’m excited for this feature so I hope we can get it done soon |
| 183 | | |
| 184 | | ''Caio:'' We still needed to add some JIT work for private fields and hopefully we can get that done soon |
| 185 | | |
| 186 | | ''Saam:'' We should just turn it on |
| 187 | | |
| 188 | | ''Yusuke:'' This is a good time to enable it because it gives us a chance to get feedback |
| 189 | | |
| 190 | | ''Caio:'' We need to do some work on field initialization but it shouldn’t block private fields because it didn’t block public fields |
| 191 | | |
| 192 | | ''Ryosuke:'' In order for the fuzzer to run with it we need to enable it somewhere e.g. WebKitTestRunner |
| 193 | | |
| 194 | | ''Yusuke:'' We need to add support private fields syntax in the fuzzer but shouldn’t be too hard |
| 195 | | |
| 196 | | ''Ryosuke:'' For each JSC feature we now want to have significant fuzzing for each new feature before shipping |
| 197 | | |
| 198 | | ''Yusuke:'' We can also enable the feature in our fuzzers without enabling by default |
| 199 | | |
| 200 | | ''Ryosuke:'' To clarify on what we want to fuzz we want to fuzz everything that could be used to exploit JSC |
| 201 | | |
| 202 | | ''Saam:'' Fortunately, for most features outside syntax, fuzzer will just test it |
| 203 | | |
| 204 | | ''Yusuke:'' Yeah, for things like changes to DFG the fuzzer will find it because it will build off all the JSC tests |
