Allow latest Composer if no lock file present

We're bumping the plugin-api-version for the no lock file present case to allow Composer 2.8 which works with PHP 8.4 (to allow clean boots, and builds without deprecation errors).

This is a very inconsequential change for users that have no lock file, as no lock file means no package installs, plugins, etc.

CHANGELOG.md

@@ -6,6 +6,10 @@
 
 - PHP/8.4.1 [David Zuelke]
 
+### CHG
+
+- Use latest Composer (instead of 2.2 LTS) if no lock file is present [David Zuelke]
+
 ## [v259] - 2024-11-21
 
 ### ADD

bin/util/platform.php

@@ -194,7 +194,9 @@ function mkmetas($package, array &$metapaks, &$have_runtime_req = false) {
 	if($metapaks) $repositories[] = ["type" => "package", "package" => $metapaks];
 } else {
 	// default to using Composer 2 if there is no lock file
-	$lock["plugin-api-version"] = "2.2.0";
+	// 2.6.0 will allow any current 2.x Composer version (see further below), which means 2.8 is possible
+	// that matters because the LTS Composer 2.2 (which we'd get if we used "2.2.0" here) throws countless deprecation warnings
+	$lock["plugin-api-version"] = "2.6.0";
 }
 
 // if no PHP is required anywhere, we need to add something

test/spec/composer-2_spec.rb

@@ -43,10 +43,10 @@
 		end
 	end
 	context "with only an index.php" do
-		it "builds using Composer 2.2" do
+		it "builds using Composer 2.3 or later" do
 			new_app_with_stack_and_platrepo('test/fixtures/default').deploy do |app|
-				expect(app.output).to match(/- composer \(2\.2\./)
-				expect(app.output).to match(/Composer version 2\.2\./)
+				expect(app.output).to match(/- composer \(2\.([3-9]|\d{2,})\./)
+				expect(app.output).to match(/Composer version 2\.([3-9]|\d{2,}\.)/)
 			end
 		end
 	end