PHPLIB-1367 Add enum for System variables

generator/config/expressions.php

@@ -125,6 +125,10 @@
         'returnType' => Type\Sort::class,
         'acceptedTypes' => [Type\Sort::class],
     ],
+    'redact' => [
+        'returnType' => Type\Redact::class,
+        'acceptedTypes' => [Type\Redact::class, ResolvesToString::class, ...$bsonTypes['string']],
+    ],
 
     // @todo add enum values
     'Granularity' => [

src/Builder/Type/Redact.php

@@ -0,0 +1,36 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Builder\Type;
+
+use MongoDB\Builder\Expression\ResolvesToString;
+
+enum Redact: string implements DictionaryInterface, ResolvesToString
+{
+    /**
+     * $redact returns the fields at the current document level, excluding embedded documents. To include embedded
+     * documents and embedded documents within arrays, apply the $cond expression to the embedded documents to determine
+     * access for these embedded documents.
+     */
+    case Descend = 'DESCEND';
+
+    /**
+     * $redact excludes all fields at this current document/embedded document level, without further inspection of any
+     * of the excluded fields. This applies even if the excluded field contains embedded documents that may have
+     * different access levels.
+     */
+    case Prune = 'PRUNE';
+
+    /**
+     * $redact returns or keeps all fields at this current document/embedded document level, without further inspection
+     * of the fields at this level. This applies even if the included field contains embedded documents that may have
+     * different access levels.
+     */
+    case Keep = 'KEEP';
+
+    public function getValue(): string
+    {
+        return '$$' . $this->value;
+    }
+}

src/Builder/Type/Variable.php

@@ -0,0 +1,58 @@
+<?php
+
+declare(strict_types=1);
+
+namespace MongoDB\Builder\Type;
+
+use MongoDB\Builder\Expression\ResolvesToAny;
+use MongoDB\Builder\Expression\Variable as VariableExpression;
+
+enum Variable: string implements DictionaryInterface, ResolvesToAny
+{
+    /**
+     * A variable that returns the current datetime value.
+     */
+    case Now = 'NOW';
+
+    /**
+     * A variable that returns the current timestamp value.
+     */
+    case ClusterTime = 'CLUSTER_TIME';
+
+    /**
+     * References the root document, i.e. the top-level document, currently being processed in the aggregation pipeline stage.
+     */
+    case Root = 'ROOT';
+
+    /**
+     * References the start of the field path being processed in the aggregation pipeline stage.
+     * Use Variable::Current->dot('field') to reference $field
+     */
+    case Current = 'CURRENT';
+
+    /**
+     * A variable which evaluates to the missing value. Allows for the conditional exclusion of fields. In a $project, a field set to the variable REMOVE is excluded from the output.
+     */
+    case Remove = 'REMOVE';
+
+    /**
+     * A variable that stores the metadata results of an Atlas Search query. In all supported aggregation pipeline
+     * stages, a field set to the variable $$SEARCH_META returns the metadata results for the query.
+     */
+    case SearchMeta = 'SEARCH_META';
+
+    /**
+     * Returns the roles assigned to the current user.
+     */
+    case UserRoles = 'USER_ROLES';
+
+    public function dot(string $name): VariableExpression
+    {
+        return new VariableExpression($this->value . '.' . $name);
+    }
+
+    public function getValue(): string
+    {
+        return '$$' . $this->value;
+    }
+}

tests/Builder/BuilderEncoderTest.php

@@ -12,8 +12,8 @@
 use MongoDB\Builder\Pipeline;
 use MongoDB\Builder\Query;
 use MongoDB\Builder\Stage;
+use MongoDB\Builder\Type\Redact;
 use MongoDB\Builder\Type\Sort;
-use MongoDB\Builder\Variable;
 use PHPUnit\Framework\TestCase;
 
 use function array_merge;
@@ -314,8 +314,8 @@ public function testRedactStage(): void
             Stage::redact(
                 Expression::cond(
                     if: Expression::eq(Expression::fieldPath('level'), 5),
-                    then: Variable::prune(),
-                    else: Variable::descend(),
+                    then: Redact::Prune,
+                    else: Redact::Descend,
                 ),
             ),
         );

tests/Builder/Expression/BsonSizeOperatorTest.php

@@ -9,6 +9,7 @@
 use MongoDB\Builder\Pipeline;
 use MongoDB\Builder\Stage;
 use MongoDB\Builder\Type\Sort;
+use MongoDB\Builder\Type\Variable;
 use MongoDB\Tests\Builder\PipelineTestCase;
 
 /**
@@ -23,7 +24,7 @@ public function testReturnCombinedSizeOfAllDocumentsInACollection(): void
                 _id: null,
                 combined_object_size: Accumulator::sum(
                     Expression::bsonSize(
-                        Expression::variable('ROOT'),
+                        Variable::Root,
                     ),
                 ),
             ),
@@ -56,7 +57,7 @@ public function testReturnSizesOfDocuments(): void
             Stage::project(
                 name: 1,
                 object_size: Expression::bsonSize(
-                    Expression::variable('ROOT'),
+                    Variable::Root,
                 ),
             ),
         );

tests/Builder/Expression/DateSubtractOperatorTest.php

@@ -9,6 +9,7 @@
 use MongoDB\Builder\Query;
 use MongoDB\Builder\Stage;
 use MongoDB\Builder\Type\TimeUnit;
+use MongoDB\Builder\Type\Variable;
 use MongoDB\Tests\Builder\PipelineTestCase;
 
 /**
@@ -83,7 +84,7 @@ public function testFilterByRelativeDates(): void
                     Expression::gt(
                         Expression::dateFieldPath('logoutTime'),
                         Expression::dateSubtract(
-                            startDate: Expression::variable('NOW'),
+                            startDate: Variable::Now,
                             unit: TimeUnit::Week,
                             amount: 1,
                         ),

tests/Builder/Expression/SetFieldOperatorTest.php

@@ -7,6 +7,7 @@
 use MongoDB\Builder\Expression;
 use MongoDB\Builder\Pipeline;
 use MongoDB\Builder\Stage;
+use MongoDB\Builder\Type\Variable;
 use MongoDB\Tests\Builder\PipelineTestCase;
 
 /**
@@ -20,7 +21,7 @@ public function testAddFieldsThatContainPeriods(): void
             Stage::replaceWith(
                 Expression::setField(
                     field: 'price.usd',
-                    input: Expression::variable('ROOT'),
+                    input: Variable::Root,
                     value: Expression::fieldPath('price'),
                 ),
             ),
@@ -36,7 +37,7 @@ public function testAddFieldsThatStartWithADollarSign(): void
             Stage::replaceWith(
                 Expression::setField(
                     field: Expression::literal('$price'),
-                    input: Expression::variable('ROOT'),
+                    input: Variable::Root,
                     value: Expression::fieldPath('price'),
                 ),
             ),
@@ -52,8 +53,8 @@ public function testRemoveFieldsThatContainPeriods(): void
             Stage::replaceWith(
                 Expression::setField(
                     field: 'price.usd',
-                    input: Expression::variable('ROOT'),
-                    value: Expression::variable('REMOVE'),
+                    input: Variable::Root,
+                    value: Variable::Remove,
                 ),
             ),
         );
@@ -67,8 +68,8 @@ public function testRemoveFieldsThatStartWithADollarSign(): void
             Stage::replaceWith(
                 Expression::setField(
                     field: Expression::literal('$price'),
-                    input: Expression::variable('ROOT'),
-                    value: Expression::variable('REMOVE'),
+                    input: Variable::Root,
+                    value: Variable::Remove,
                 ),
             ),
         );
@@ -85,7 +86,7 @@ public function testUpdateFieldsThatContainPeriods(): void
             Stage::replaceWith(
                 Expression::setField(
                     field: 'price.usd',
-                    input: Expression::variable('ROOT'),
+                    input: Variable::Root,
                     value: 49.99,
                 ),
             ),
@@ -103,7 +104,7 @@ public function testUpdateFieldsThatStartWithADollarSign(): void
             Stage::replaceWith(
                 Expression::setField(
                     field: Expression::literal('$price'),
-                    input: Expression::variable('ROOT'),
+                    input: Variable::Root,
                     value: 49.99,
                 ),
             ),