Fix CI: non-semver compliant Yarn versions

[Timer]

/cc @arcanis

> require('semver').gte('v1.13.0-a20181006.0202', '1.1.0')
TypeError: Invalid Version: v1.13.0-a20181006.0202
    at new SemVer (/Users/joe/Documents/Development/OSS/create-react-app/node_modules/semver/semver.js:305:11)
    at compare (/Users/joe/Documents/Development/OSS/create-react-app/node_modules/semver/semver.js:578:10)
    at Function.gte (/Users/joe/Documents/Development/OSS/create-react-app/node_modules/semver/semver.js:627:10)
> require('semver').gte('v1.13.0-a201810060202', '1.1.0')
true
> require('semver').gte('v1.13.0-a20181006+0202', '1.1.0')
true
> require('semver').gte('v1.13.0-a20181006-0202', '1.1.0')
true

[arcanis]

cc @Daniel15 maybe we should replace the dot by a dash on nightlies?

[Daniel15]

@arcanis Yarn's current nightly versioning is semver compliant. See section 9 of the semver spec:

A pre-release version MAY be denoted by appending a hyphen and a series of dot separated identifiers immediately following the patch version. Identifiers MUST comprise only ASCII alphanumerics and hyphen [0-9A-Za-z-]. Identifiers MUST NOT be empty [...] Examples: 1.0.0-alpha, 1.0.0-alpha.1, 1.0.0-0.3.7, 1.0.0-x.7.z.92.

Date and time are separate identifiers, so they're correctly separated by dots.

@Timer Where does that version number come from? I don't think the Yarn version numbers start with v or have an a in them. It should look like 1.13.0-20181006.0202.

[Timer]

@Daniel15 this is coming from running yarnpkg --version

[Daniel15]

@Timer I can't repro:

C:\temp
λ curl https://nightly.yarnpkg.com/latest.js -L -o yarn.js
  % Total    % Received % Xferd  Average Speed   Time    Time     Time  Current
                                 Dload  Upload   Total   Spent    Left  Speed
  0     0    0     0    0     0      0      0 --:--:-- --:--:-- --:--:--     0
100 4365k    0 4365k    0     0  3592k      0 --:--:--  0:00:01 --:--:-- 13.4M

C:\temp
λ node .\yarn.js --version
1.13.0-20181009.1747

Which the semver module says is valid:

λ node
> require('semver').valid('1.13.0-20181009.1747')
'1.13.0-20181009.1747'

[arcanis]

@Timer is right, the gte function throws an exception even if valid passes 🤷‍♀️

Cf https://runkit.com/arcanis/5bbd1c8c1b4bc50012da3645

[Daniel15]

@arcanis Your example code uses a different version string format for the gte function than for the valid function. The gte call has an "a" before the date. -- Regards, Daniel Lo Nigro https://dan.cx/ | Twitter <http://twitter.com/Daniel15> | Facebook <http://www.facebook.com/daaniel>

…

On Tue, Oct 9, 2018 at 2:25 PM Maël Nison ***@***.***> wrote: @Timer <https://github.com/Timer> is right, the gte function throws an exception even if valid passes 🤷‍♀️ Cf https://runkit.com/arcanis/5bbd1c8c1b4bc50012da3645 — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#5362 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAFnHURBg_YgzdTSSaKXyR7UppRZ_qN7ks5ujRRHgaJpZM4XNw63> .

[arcanis]

Oooh I found the issue. It's even better than I thought. It's not the . that's at fault, nor the a. It's the 0 that follows the dot. That's why @Timer got the issue: his nightly at the time he made the PR ended with 0202. After he upgraded later on he got 1747, and when you tried to reproduce with this version it worked. Check this:

Works:

console.log(require('semver').gte('1.13.0-20181009.1747', '1.1.0'))

Breaks:

console.log(require('semver').gte('1.13.0-20181006.0202', '1.1.0'))

Similarly, if you check 0202 with valid, you'll get null:

console.log(require('semver').valid('1.13.0-20181006.0202'))

[Daniel15]

Hahahaha what. Is that a bug in the semver package? I don't see why that'd be invalid.

[arcanis]

Looking at the grammar, it seems invalid. Notice how <numeric identifier> cannot start by 0 unless it's the only digit. Very unintuitive:

<pre-release> ::= <dot-separated pre-release identifiers>

<dot-separated pre-release identifiers> ::= <pre-release identifier>
                                          | <pre-release identifier> "." <dot-separated pre-release identifiers>

<pre-release identifier> ::= <alphanumeric identifier>
                           | <numeric identifier>

<numeric identifier> ::= "0"
                       | <positive digit>
                       | <positive digit> <digits>

<positive digit> ::= "1" | "2" | "3" | "4" | "5" | "6" | "7" | "8" | "9"

[Daniel15]

Where is that grammar from?

I don't see this documented at https://semver.org/ :/

[arcanis]

On the github repo: https://github.com/semver/semver/blob/master/semver.md#backusnaur-form-grammar-for-valid-semver-versions

Funnily, if the faulty 0202 was followed by any alpha character, it would become an alphanumeric identifier and would become valid. So we could make it 02h02m for example 😄

[iansu]

Is this maybe because a number that starts with 0 is considered to be octal? That's all I can come up with. 🤷‍♂️