Support Composer 2 and add 2.0.7

Closes #440

CHANGELOG.md

@@ -2,6 +2,11 @@
 
 ## v184 (2020-11-20)
 
+### ADD
+
+- Support for Composer 2 (#440) [David Zuelke]
+- Composer/2.0.7 [David Zuelke]
+
 ### CHG
 
 - Install Composer using platform installer [David Zuelke]

support/build/composer-2.0.7

@@ -0,0 +1,5 @@
+#!/usr/bin/env bash
+# Build Path: /app/.heroku/php
+# Build Deps: php-min-*
+
+source $(dirname $0)/composer

test/fixtures/composer/basic_lock_oldv1/composer.json

@@ -0,0 +1,5 @@
+{
+    "require": {
+        "php": "7.3.*"
+    }
+}

test/fixtures/composer/basic_lock_v1/composer.json

@@ -0,0 +1,5 @@
+{
+    "require": {
+        "php": "7.3.*"
+    }
+}

test/fixtures/composer/basic_lock_v2/composer.json

@@ -0,0 +1,5 @@
+{
+    "require": {
+        "php": "7.3.*"
+    }
+}

test/spec/composer_spec.rb

@@ -0,0 +1,28 @@
+require_relative "spec_helper"
+
+describe "A PHP application" do
+	context "with a composer.lock generatead by an old version of Composer" do
+		it "builds using Composer 1.x" do
+			new_app_with_stack_and_platrepo('test/fixtures/composer/basic_lock_oldv1').deploy do |app|
+				expect(app.output).to match(/- composer \(1/)
+				expect(app.output).to match(/Composer version 1/)
+			end
+		end
+	end
+	context "with a composer.lock generatead by a late version 1 of Composer" do
+		it "builds using Composer 1.x" do
+			new_app_with_stack_and_platrepo('test/fixtures/composer/basic_lock_v1').deploy do |app|
+				expect(app.output).to match(/- composer \(1/)
+				expect(app.output).to match(/Composer version 1/)
+			end
+		end
+	end
+	context "with a composer.lock generatead by version 2 of Composer" do
+		it "builds using Composer 2.x" do
+			new_app_with_stack_and_platrepo('test/fixtures/composer/basic_lock_v2').deploy do |app|
+				expect(app.output).to match(/- composer \(2/)
+				expect(app.output).to match(/Composer version 2/)
+			end
+		end
+	end
+end