[EWS] "Try Build" button should take a pull request number, not patch ID.

https://bugs.webkit.org/show_bug.cgi?id=301594
rdar://163593230

Reviewed by Ryan Haddad.

The "Try Build" button on EWS currently takes a Bugzilla patch ID. In an effort
to modernize this workflow, this change implements manual run triggering from
PR number instead of patch ID.

* Tools/CISupport/ews-build/loadConfig.py:
    (loadBuilderConfig): Change "Try Build" workflow to accept PR number.
* Tools/CISupport/ews-build/steps.py:
    (ValidateChange):
        -> (run): Add support for ingesting PR number from `pr_number` property.
        -> (validate_github): Populate GitHub data from `pr_json` if absent.

Canonical link: https://commits.webkit.org/302304@main

Author: bls1999

Tools/CISupport/ews-build/loadConfig.py

@@ -111,7 +111,7 @@ def filter_fn(change, schedulerName=schedulerName):
     forceScheduler = ForceScheduler(
         name='try_build',
         buttonName='Try Build',
-        reason=StringParameter(name='reason', default='Trying patch', size=20),
+        reason=StringParameter(name='reason', default='Trying pull request', size=20),
         builderNames=[str(builder['name']) for builder in config['builders']],
         # Disable default enabled input fields: branch, repository, project, additional properties
         codebases=[CodebaseParameter('',
@@ -120,7 +120,7 @@ def filter_fn(change, schedulerName=schedulerName):
                    project=FixedParameter(name='project', default=''),
                    branch=FixedParameter(name='branch', default=''))],
         # Add custom properties needed
-        properties=[StringParameter(name='patch_id', label='Patch id (not bug number)', regex=r'^[4-9]\d{5}$', required=True, maxsize=6),
+        properties=[StringParameter(name='pr_number', label='Pull Request number (not bug number)', regex=r'^[0-9]{5,6}$', required=True, maxsize=6),
                     StringParameter(name='ews_revision', label='WebKit git hash to checkout before trying patch (optional)', required=False, maxsize=40)],
     )
     if setup_force_schedulers is True:

Tools/CISupport/ews-build/steps.py

@@ -1874,7 +1874,7 @@ def fail_build(self, reason):
     @defer.inlineCallbacks
     def run(self):
         patch_id = self.getProperty('patch_id', '')
-        pr_number = self.getProperty('github.number', '')
+        pr_number = self.getProperty('github.number', self.getProperty('pr_number', ''))
         branch = self.getProperty('github.base.ref', DEFAULT_BRANCH)
 
         if not any(candidate.match(branch) for candidate in self.branches):
@@ -1971,6 +1971,18 @@ def validate_github(self, pr_number):
         pr_json = yield self.get_pr_json(pr_number, repository_url, retry=3)
 
         if pr_json:
+            # Manually triggered from "Try build" button, manually populate data
+            if not self.getProperty('github.number', ''):
+                self.setProperty('github.base.ref', pr_json['base']['ref'])
+                self.setProperty('github.head.ref', pr_json['head']['ref'])
+                self.setProperty('github.head.repo.full_name', pr_json['head']['repo']['full_name'])
+                self.setProperty('github.head.sha', pr_json['head']['sha'])
+                self.setProperty('github.head.user.login', pr_json['head']['user']['login'])
+                self.setProperty('github.number', pr_json['number'])
+                self.setProperty('github.title', pr_json['title'])
+                self.setProperty('owners', [pr_json['head']['user']['login']])
+                yield ConfigureBuild.add_pr_details(self)
+
             # Only track actionable labels, since bug category labels may reveal information about security bugs
             self.setProperty('github_labels', [
                 data.get('name')