Allow global ignore-platform-req (#10616)

doc/03-cli.md

@@ -1174,3 +1174,11 @@ useful for plugin authors to identify what is firing when exactly.
 
 If set to `1`, it is the equivalent of passing the `--no-dev` argument to `install` or
 `update`. You can override this for a single command by setting `COMPOSER_NO_DEV=0`.
+
+### COMPOSER_IGNORE_PLATFORM_REQ or COMPOSER_IGNORE_PLATFORM_REQS
+
+If `COMPOSER_IGNORE_PLATFORM_REQS` set to `1`, it is the equivalent of passing the `--ignore-platform-reqs` argument.
+Otherwise, specifying a comma separated list in `COMPOSER_IGNORE_PLATFORM_REQ` will ignore those specific requirements.
+
+For example, if a development workstation will never run database queries, this can be used to ignore the requirement for the database extensions to be available.
+If you set `COMPOSER_IGNORE_PLATFORM_REQ=ext-oci8`, then composer will allow packages to be installed even if the `oci8` PHP extension is not enabled.

src/Composer/Command/BaseCommand.php

@@ -198,6 +198,8 @@ abstract class BaseCommand extends Command
         }
 
         $composer = $this->tryComposer($disablePlugins, $disableScripts);
+        $io = $this->getIO();
+
         if (null === $composer) {
             $composer = Factory::createGlobal($this->getIO(), $disablePlugins, $disableScripts);
         }
@@ -210,12 +212,29 @@ abstract class BaseCommand extends Command
             $input->setOption('no-progress', true);
         }
 
-        if (true == $input->hasOption('no-dev')) {
+        if (true === $input->hasOption('no-dev')) {
             if (!$input->getOption('no-dev') && true == Platform::getEnv('COMPOSER_NO_DEV')) {
                 $input->setOption('no-dev', true);
             }
         }
 
+        if (true === $input->hasOption('ignore-platform-reqs')) {
+            if (!$input->getOption('ignore-platform-reqs') && true == Platform::getEnv('COMPOSER_IGNORE_PLATFORM_REQS')) {
+                $input->setOption('ignore-platform-reqs', true);
+
+                $io->writeError('<warning>COMPOSER_IGNORE_PLATFORM_REQS is set. You may experience unexpected errors.</warning>');
+            }
+        }
+
+        if (true === $input->hasOption('ignore-platform-req') && (!$input->hasOption('ignore-platform-reqs') || !$input->getOption('ignore-platform-reqs'))) {
+            $ignorePlatformReqEnv = Platform::getEnv('COMPOSER_IGNORE_PLATFORM_REQ');
+            if (0 === count($input->getOption('ignore-platform-req')) && is_string($ignorePlatformReqEnv) && '' !== $ignorePlatformReqEnv) {
+                $input->setOption('ignore-platform-req', explode(',', $ignorePlatformReqEnv));
+
+                $io->writeError('<warning>COMPOSER_IGNORE_PLATFORM_REQ is set to ignore '.$ignorePlatformReqEnv.'. You may experience unexpected errors.</warning>');
+            }
+        }
+
         parent::initialize($input, $output);
     }