rubysrc2cpg: handle empty arrays (#3207)

* handle empty array in rhs of assignment * add arrayInitializer with no children * add test for empty array in block
joernio · Jul 26, 2023 · bacba5c · bacba5c
1 parent c4acc14
commit bacba5c
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Showing 3 changed files with 37 additions and 4 deletions.
diff --git a/...li/frontends/rubysrc2cpg/src/main/scala/io/joern/rubysrc2cpg/astcreation/AstCreator.scala b/...li/frontends/rubysrc2cpg/src/main/scala/io/joern/rubysrc2cpg/astcreation/AstCreator.scala
@@ -508,7 +508,18 @@ class AstCreator(
   }
 
   def astForArrayConstructorPrimaryContext(ctx: ArrayConstructorPrimaryContext): Seq[Ast] = {
-    astForIndexingArgumentsContext(ctx.arrayConstructor().indexingArguments())
+    if (ctx.getText == "[]") {
+      /* we might have an empty array, so create an empty as there would be no indexing args */
+      val arrayInitCallNode = NewCall()
+        .name(Operators.arrayInitializer)
+        .methodFullName(Operators.arrayInitializer)
+        .signature(Operators.arrayInitializer)
+        .typeFullName(Defines.Any)
+        .dispatchType(DispatchTypes.STATIC_DISPATCH)
+      Seq(callAst(arrayInitCallNode))
+    } else {
+      astForIndexingArgumentsContext(ctx.arrayConstructor().indexingArguments())
+    }
   }
 
   def astForBeginExpressionPrimaryContext(ctx: BeginExpressionPrimaryContext): Seq[Ast] = {

diff --git a/...frontends/rubysrc2cpg/src/test/scala/io/joern/rubysrc2cpg/passes/ast/AssignCpgTests.scala b/...frontends/rubysrc2cpg/src/test/scala/io/joern/rubysrc2cpg/passes/ast/AssignCpgTests.scala
@@ -1,7 +1,7 @@
 package io.joern.rubysrc2cpg.passes.ast
 
 import io.joern.rubysrc2cpg.testfixtures.RubyCode2CpgFixture
-import io.shiftleft.codepropertygraph.generated.{EvaluationStrategies, NodeTypes, DispatchTypes, Operators, nodes}
+import io.shiftleft.codepropertygraph.generated.{DispatchTypes, EvaluationStrategies, NodeTypes, Operators, nodes}
 import io.shiftleft.semanticcpg.language.*
 import io.shiftleft.semanticcpg.language.types.structure.NamespaceTraversal
 
@@ -173,4 +173,14 @@ class AssignCpgTests extends RubyCode2CpgFixture {
       tmpAssignNode.lineNumber shouldBe Some(1)
     }
   }
+
+  "empty array assignment" should {
+    val cpg = code("""x.y = []""".stripMargin)
+
+    "have an empty assignment" in {
+      val List(assignment) = cpg.call.name(Operators.assignment).l
+      assignment.argument.where(_.argumentIndex(2)).isCall.name.l shouldBe List(Operators.arrayInitializer)
+      assignment.argument.where(_.argumentIndex(2)).isCall.argument.l shouldBe List()
+    }
+  }
 }
diff --git a/...frontends/rubysrc2cpg/src/test/scala/io/joern/rubysrc2cpg/passes/ast/MethodOneTests.scala b/...frontends/rubysrc2cpg/src/test/scala/io/joern/rubysrc2cpg/passes/ast/MethodOneTests.scala
@@ -1,8 +1,7 @@
 package io.joern.rubysrc2cpg.passes.ast
 
 import io.joern.rubysrc2cpg.testfixtures.RubyCode2CpgFixture
-import io.shiftleft.codepropertygraph.generated.EvaluationStrategies
-import io.shiftleft.codepropertygraph.generated.NodeTypes
+import io.shiftleft.codepropertygraph.generated.{EvaluationStrategies, NodeTypes, Operators}
 import io.shiftleft.semanticcpg.language.*
 import io.shiftleft.semanticcpg.language.types.structure.NamespaceTraversal
 
@@ -121,4 +120,17 @@ class MethodOneTests extends RubyCode2CpgFixture {
       }
     }
   }
+
+  "Function with empty array in block" should {
+    val cpg = code("""
+        |def foo
+        |  []
+        |end
+        |""".stripMargin)
+
+    "contain empty array" in {
+      cpg.method.name("foo").size shouldBe 1
+      cpg.method.name("foo").block.containsCallTo(Operators.arrayInitializer).size shouldBe 1
+    }
+  }
 }