Merge pull request #7283 from aibaars/ruby-pattern-matching-cfg

Ruby: pattern matching: CFG
2025-12-17 01:03:14 +01:00 · 2021-12-10 10:24:38 +01:00
parent 634ed91904 fd4915a564
commit 13f7fd88f1
13 changed files with 1364 additions and 44 deletions
--- a/ruby/ql/lib/codeql/ruby/ast/internal/AST.qll
+++ b/ruby/ql/lib/codeql/ruby/ast/internal/AST.qll
@@ -246,8 +246,6 @@ private module Cached {
        explicitAssignmentNode(g, _)
        or
        casePattern(g)
-        or
-        classReferencePattern(g)
      )
    } or
    TScopeResolutionMethodCall(Ruby::ScopeResolution g, Ruby::Identifier i) {
@@ -293,8 +291,6 @@ private module Cached {
      explicitAssignmentNode(g, _)
      or
      casePattern(g)
-      or
-      classReferencePattern(g)
    } or
    TTokenMethodName(MethodName::Token g) { MethodName::range(g) } or
    TTokenSuperCall(Ruby::Super g) { vcall(g) } or
--- a/ruby/ql/lib/codeql/ruby/ast/internal/Pattern.qll
+++ b/ruby/ql/lib/codeql/ruby/ast/internal/Pattern.qll
@@ -48,13 +48,7 @@ predicate casePattern(Ruby::AstNode node) {
  node = any(Ruby::KeywordPattern parent).getValue()
  or
  node = any(Ruby::ParenthesizedPattern parent).getChild()
-}
-
-/**
- * Holds if `node` is a class reference used in an
- * array, find, or hash pattern.
- */
-predicate classReferencePattern(Ruby::AstNode node) {
+  or
  node = any(Ruby::ArrayPattern p).getClass()
  or
  node = any(Ruby::FindPattern p).getClass()
--- a/ruby/ql/lib/codeql/ruby/controlflow/internal/Completion.qll
+++ b/ruby/ql/lib/codeql/ruby/controlflow/internal/Completion.qll
@@ -6,6 +6,7 @@

 private import codeql.ruby.AST
 private import codeql.ruby.ast.internal.AST
+private import codeql.ruby.ast.internal.Control
 private import codeql.ruby.controlflow.ControlFlowGraph
 private import ControlFlowGraphImpl
 private import NonReturning
@@ -27,6 +28,10 @@ private newtype TCompletion =
    outer instanceof NonNestedNormalCompletion and
    nestLevel = 0
    or
+    inner instanceof TBooleanCompletion and
+    outer instanceof TMatchingCompletion and
+    nestLevel = 0
+    or
    inner instanceof NormalCompletion and
    nestedEnsureCompletion(outer, nestLevel)
  }
@@ -81,8 +86,9 @@ private predicate mayRaise(Call c) {

 /** A completion of a statement or an expression. */
 abstract class Completion extends TCompletion {
-  /** Holds if this completion is valid for node `n`. */
-  predicate isValidFor(AstNode n) {
+  private predicate isValidForSpecific(AstNode n) {
+    exists(AstNode other | n = other.getDesugared() and this.isValidForSpecific(other))
+    or
    this = n.(NonReturningCall).getACompletion()
    or
    completionIsValidForStmt(n, this)
@@ -98,15 +104,26 @@ abstract class Completion extends TCompletion {
    mustHaveMatchingCompletion(n) and
    this = TMatchingCompletion(_)
    or
-    n = any(RescueModifierExpr parent).getBody() and this = TRaiseCompletion()
+    n = any(RescueModifierExpr parent).getBody() and
+    this = [TSimpleCompletion().(TCompletion), TRaiseCompletion()]
    or
-    mayRaise(n) and
-    this = TRaiseCompletion()
+    (
+      mayRaise(n)
+      or
+      n instanceof CaseMatch and not exists(n.(CaseExpr).getElseBranch())
+    ) and
+    (
+      this = TRaiseCompletion()
+      or
+      this = TSimpleCompletion() and not n instanceof NonReturningCall
+    )
+  }
+
+  /** Holds if this completion is valid for node `n`. */
+  predicate isValidFor(AstNode n) {
+    this.isValidForSpecific(n)
    or
-    not n instanceof NonReturningCall and
-    not completionIsValidForStmt(n, _) and
-    not mustHaveBooleanCompletion(n) and
-    not mustHaveMatchingCompletion(n) and
+    not any(Completion c).isValidForSpecific(n) and
    this = TSimpleCompletion()
  }

@@ -172,6 +189,8 @@ private predicate inBooleanContext(AstNode n) {
  or
  n = any(ConditionalLoop parent).getCondition()
  or
+  n = any(InClause parent).getCondition()
+  or
  exists(LogicalAndExpr parent |
    n = parent.getLeftOperand()
    or
@@ -218,6 +237,10 @@ private predicate inMatchingContext(AstNode n) {
    w.getPattern(_) = n
  )
  or
+  n instanceof CasePattern
+  or
+  n = any(VariableReferencePattern p).getVariableAccess()
+  or
  n.(Trees::DefaultValueParameterTree).hasDefaultValue()
 }

@@ -241,7 +264,7 @@ class SimpleCompletion extends NonNestedNormalCompletion, TSimpleCompletion {
 * the successor. Either a Boolean completion (`BooleanCompletion`), or a matching
 * completion (`MatchingCompletion`).
 */
-abstract class ConditionalCompletion extends NonNestedNormalCompletion {
+abstract class ConditionalCompletion extends NormalCompletion {
  boolean value;

  bindingset[value]
@@ -255,7 +278,7 @@ abstract class ConditionalCompletion extends NonNestedNormalCompletion {
 * A completion that represents evaluation of an expression
 * with a Boolean value.
 */
-class BooleanCompletion extends ConditionalCompletion, TBooleanCompletion {
+class BooleanCompletion extends ConditionalCompletion, NonNestedNormalCompletion, TBooleanCompletion {
  BooleanCompletion() { this = TBooleanCompletion(value) }

  /** Gets the dual Boolean completion. */
@@ -280,10 +303,16 @@ class FalseCompletion extends BooleanCompletion {
 * A completion that represents evaluation of a matching test, for example
 * a test in a `rescue` statement.
 */
-class MatchingCompletion extends ConditionalCompletion, TMatchingCompletion {
-  MatchingCompletion() { this = TMatchingCompletion(value) }
+class MatchingCompletion extends ConditionalCompletion {
+  MatchingCompletion() {
+    this = TMatchingCompletion(value)
+    or
+    this = TNestedCompletion(_, TMatchingCompletion(value), _)
+  }

-  override MatchingSuccessor getAMatchingSuccessorType() { result.getValue() = value }
+  override ConditionalSuccessor getAMatchingSuccessorType() {
+    this = TMatchingCompletion(result.(MatchingSuccessor).getValue())
+  }

  override string toString() { if value = true then result = "match" else result = "no-match" }
 }
@@ -440,7 +469,9 @@ abstract class NestedCompletion extends Completion, TNestedCompletion {
  NestedCompletion() { this = TNestedCompletion(inner, outer, nestLevel) }

  /** Gets a completion that is compatible with the inner completion. */
-  abstract Completion getAnInnerCompatibleCompletion();
+  Completion getAnInnerCompatibleCompletion() {
+    result.getOuterCompletion() = this.getInnerCompletion()
+  }

  /** Gets the level of this nested completion. */
  final int getNestLevel() { result = nestLevel }
@@ -483,9 +514,39 @@ class NestedEnsureCompletion extends NestedCompletion {

  override Completion getOuterCompletion() { result = outer }

-  override Completion getAnInnerCompatibleCompletion() {
-    result.getOuterCompletion() = this.getInnerCompletion()
-  }
-
  override SuccessorType getAMatchingSuccessorType() { none() }
 }
+
+/**
+ * A completion used for conditions in pattern matching:
+ *
+ * ```rb
+ * in x if x == 5 then puts "five"
+ * in x unless x == 4 then puts "not four"
+ * ```
+ *
+ * The outer (Matching) completion indicates whether there is a match, and
+ * the inner (Boolean) completion indicates what the condition evaluated
+ * to.
+ *
+ * For the condition `x == 5` above, `TNestedCompletion(true, true, 0)` and
+ * `TNestedCompletion(false, false, 0)` are both valid completions, while
+ * `TNestedCompletion(true, false, 0)` and `TNestedCompletion(false, true, 0)`
+ * are valid completions for `x == 4`.
+ */
+class NestedMatchingCompletion extends NestedCompletion, MatchingCompletion {
+  NestedMatchingCompletion() {
+    inner instanceof TBooleanCompletion and
+    outer instanceof TMatchingCompletion
+  }
+
+  override BooleanCompletion getInnerCompletion() { result = inner }
+
+  override MatchingCompletion getOuterCompletion() { result = outer }
+
+  override BooleanSuccessor getAMatchingSuccessorType() {
+    result.getValue() = this.getInnerCompletion().getValue()
+  }
+
+  override string toString() { result = NestedCompletion.super.toString() }
+}
--- a/ruby/ql/lib/codeql/ruby/controlflow/internal/ControlFlowGraphImpl.qll
+++ b/ruby/ql/lib/codeql/ruby/controlflow/internal/ControlFlowGraphImpl.qll
@@ -419,6 +419,387 @@ module Trees {
    }
  }

+  private class CaseMatchTree extends PreOrderTree, CaseExpr, ASTInternal::TCaseMatch {
+    final override predicate propagatesAbnormal(AstNode child) {
+      child = this.getValue() or child = this.getABranch()
+    }
+
+    final override predicate last(AstNode last, Completion c) {
+      last(this.getABranch(), last, c) and
+      not c.(MatchingCompletion).getValue() = false
+      or
+      not exists(this.getElseBranch()) and
+      exists(MatchingCompletion lc, Expr lastBranch |
+        lastBranch = max(int i | | this.getBranch(i) order by i) and
+        lc.getValue() = false and
+        last(lastBranch, last, lc) and
+        c instanceof RaiseCompletion and
+        not c instanceof NestedCompletion
+      )
+    }
+
+    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
+      pred = this and
+      first(this.getValue(), succ) and
+      c instanceof SimpleCompletion
+      or
+      last(this.getValue(), pred, c) and
+      first(this.getBranch(0), succ) and
+      c instanceof SimpleCompletion
+      or
+      exists(int i, Expr branch | branch = this.getBranch(i) |
+        last(branch, pred, c) and
+        first(this.getBranch(i + 1), succ) and
+        c.(MatchingCompletion).getValue() = false
+      )
+    }
+  }
+
+  private class PatternVariableAccessTree extends LocalVariableAccessTree, LocalVariableWriteAccess,
+    CasePattern {
+    final override predicate last(AstNode last, Completion c) {
+      super.last(last, c) and
+      c.(MatchingCompletion).getValue() = true
+    }
+  }
+
+  private class ArrayPatternTree extends ControlFlowTree, ArrayPattern {
+    final override predicate propagatesAbnormal(AstNode child) {
+      child = this.getClass() or
+      child = this.getPrefixElement(_) or
+      child = this.getRestVariableAccess() or
+      child = this.getSuffixElement(_)
+    }
+
+    final override predicate first(AstNode first) {
+      first(this.getClass(), first)
+      or
+      not exists(this.getClass()) and first = this
+    }
+
+    final override predicate last(AstNode last, Completion c) {
+      c.(MatchingCompletion).getValue() = false and
+      (
+        last = this and
+        c.isValidFor(this)
+        or
+        exists(AstNode node |
+          node = this.getClass() or
+          node = this.getPrefixElement(_) or
+          node = this.getSuffixElement(_)
+        |
+          last(node, last, c)
+        )
+      )
+      or
+      c.(MatchingCompletion).getValue() = true and
+      last = this and
+      c.isValidFor(this) and
+      not exists(this.getPrefixElement(_)) and
+      not exists(this.getRestVariableAccess())
+      or
+      c.(MatchingCompletion).getValue() = true and
+      last(max(int i | | this.getPrefixElement(i) order by i), last, c) and
+      not exists(this.getRestVariableAccess())
+      or
+      last(this.getRestVariableAccess(), last, c) and
+      not exists(this.getSuffixElement(_))
+      or
+      c.(MatchingCompletion).getValue() = true and
+      last(max(int i | | this.getSuffixElement(i) order by i), last, c)
+    }
+
+    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
+      last(this.getClass(), pred, c) and
+      succ = this and
+      c.(MatchingCompletion).getValue() = true
+      or
+      exists(AstNode next |
+        pred = this and
+        c.(MatchingCompletion).getValue() = true and
+        first(next, succ)
+      |
+        next = this.getPrefixElement(0)
+        or
+        not exists(this.getPrefixElement(_)) and
+        next = this.getRestVariableAccess()
+      )
+      or
+      last(max(int i | | this.getPrefixElement(i) order by i), pred, c) and
+      first(this.getRestVariableAccess(), succ) and
+      c.(MatchingCompletion).getValue() = true
+      or
+      exists(int i |
+        last(this.getPrefixElement(i), pred, c) and
+        first(this.getPrefixElement(i + 1), succ) and
+        c.(MatchingCompletion).getValue() = true
+      )
+      or
+      last(this.getRestVariableAccess(), pred, c) and
+      first(this.getSuffixElement(0), succ) and
+      c instanceof SimpleCompletion
+      or
+      exists(int i |
+        last(this.getSuffixElement(i), pred, c) and
+        first(this.getSuffixElement(i + 1), succ) and
+        c.(MatchingCompletion).getValue() = true
+      )
+    }
+  }
+
+  private class FindPatternTree extends ControlFlowTree, FindPattern {
+    final override predicate propagatesAbnormal(AstNode child) {
+      child = this.getClass() or
+      child = this.getPrefixVariableAccess() or
+      child = this.getElement(_) or
+      child = this.getSuffixVariableAccess()
+    }
+
+    final override predicate first(AstNode first) {
+      first(this.getClass(), first)
+      or
+      not exists(this.getClass()) and first = this
+    }
+
+    final override predicate last(AstNode last, Completion c) {
+      last(this.getSuffixVariableAccess(), last, c)
+      or
+      last(max(int i | | this.getElement(i) order by i), last, c) and
+      not exists(this.getSuffixVariableAccess())
+      or
+      c.(MatchingCompletion).getValue() = false and
+      (
+        last = this and
+        c.isValidFor(this)
+        or
+        exists(AstNode node | node = this.getClass() or node = this.getElement(_) |
+          last(node, last, c)
+        )
+      )
+    }
+
+    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
+      last(this.getClass(), pred, c) and
+      succ = this and
+      c.(MatchingCompletion).getValue() = true
+      or
+      exists(AstNode next |
+        pred = this and
+        c.(MatchingCompletion).getValue() = true and
+        first(next, succ)
+      |
+        next = this.getPrefixVariableAccess()
+        or
+        not exists(this.getPrefixVariableAccess()) and
+        next = this.getElement(0)
+      )
+      or
+      last(this.getPrefixVariableAccess(), pred, c) and
+      first(this.getElement(0), succ) and
+      c instanceof SimpleCompletion
+      or
+      c.(MatchingCompletion).getValue() = true and
+      exists(int i |
+        last(this.getElement(i), pred, c) and
+        first(this.getElement(i + 1), succ)
+      )
+      or
+      c.(MatchingCompletion).getValue() = true and
+      last(max(int i | | this.getElement(i) order by i), pred, c) and
+      first(this.getSuffixVariableAccess(), succ)
+    }
+  }
+
+  private class HashPatternTree extends ControlFlowTree, HashPattern {
+    final override predicate propagatesAbnormal(AstNode child) {
+      child = this.getClass() or
+      child = this.getValue(_) or
+      child = this.getRestVariableAccess()
+    }
+
+    final override predicate first(AstNode first) {
+      first(this.getClass(), first)
+      or
+      not exists(this.getClass()) and first = this
+    }
+
+    final override predicate last(AstNode last, Completion c) {
+      c.(MatchingCompletion).getValue() = false and
+      (
+        last = this and
+        c.isValidFor(this)
+        or
+        exists(AstNode node |
+          node = this.getClass() or
+          node = this.getValue(_)
+        |
+          last(node, last, c)
+        )
+      )
+      or
+      c.(MatchingCompletion).getValue() = true and
+      last = this and
+      not exists(this.getValue(_)) and
+      not exists(this.getRestVariableAccess())
+      or
+      c.(MatchingCompletion).getValue() = true and
+      last(max(int i | | this.getValue(i) order by i), last, c) and
+      not exists(this.getRestVariableAccess())
+      or
+      last(this.getRestVariableAccess(), last, c)
+    }
+
+    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
+      last(this.getClass(), pred, c) and
+      succ = this and
+      c.(MatchingCompletion).getValue() = true
+      or
+      exists(AstNode next |
+        pred = this and
+        c.(MatchingCompletion).getValue() = true and
+        first(next, succ)
+      |
+        next = this.getValue(0)
+        or
+        not exists(this.getValue(_)) and
+        next = this.getRestVariableAccess()
+      )
+      or
+      last(max(int i | | this.getValue(i) order by i), pred, c) and
+      first(this.getRestVariableAccess(), succ) and
+      c.(MatchingCompletion).getValue() = true
+      or
+      exists(int i |
+        last(this.getValue(i), pred, c) and
+        first(this.getValue(i + 1), succ) and
+        c.(MatchingCompletion).getValue() = true
+      )
+    }
+  }
+
+  private class LineLiteralTree extends LeafTree, LineLiteral { }
+
+  private class FileLiteralTree extends LeafTree, FileLiteral { }
+
+  private class EncodingLiteralTree extends LeafTree, EncodingLiteral { }
+
+  private class AlternativePatternTree extends PreOrderTree, AlternativePattern {
+    final override predicate propagatesAbnormal(AstNode child) { child = this.getAnAlternative() }
+
+    final override predicate last(AstNode last, Completion c) {
+      last(this.getAnAlternative(), last, c) and
+      c.(MatchingCompletion).getValue() = true
+      or
+      last(max(int i | | this.getAlternative(i) order by i), last, c) and
+      c.(MatchingCompletion).getValue() = false
+    }
+
+    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
+      pred = this and
+      first(this.getAlternative(0), succ) and
+      c instanceof SimpleCompletion
+      or
+      exists(int i |
+        last(this.getAlternative(i), pred, c) and
+        first(this.getAlternative(i + 1), succ) and
+        c.(MatchingCompletion).getValue() = false
+      )
+    }
+  }
+
+  private class AsPatternTree extends PreOrderTree, AsPattern {
+    final override predicate propagatesAbnormal(AstNode child) { child = this.getPattern() }
+
+    final override predicate last(AstNode last, Completion c) {
+      last(this.getPattern(), last, c) and
+      c.(MatchingCompletion).getValue() = false
+      or
+      last(this.getVariableAccess(), last, c)
+    }
+
+    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
+      pred = this and
+      first(this.getPattern(), succ) and
+      c instanceof SimpleCompletion
+      or
+      last(this.getPattern(), pred, c) and
+      first(this.getVariableAccess(), succ) and
+      c.(MatchingCompletion).getValue() = true
+    }
+  }
+
+  private class ParenthesizedPatternTree extends StandardPreOrderTree, ParenthesizedPattern {
+    override ControlFlowTree getChildElement(int i) { result = this.getPattern() and i = 0 }
+  }
+
+  private class VariableReferencePatternTree extends StandardPreOrderTree, VariableReferencePattern {
+    override ControlFlowTree getChildElement(int i) { result = this.getVariableAccess() and i = 0 }
+  }
+
+  private class InClauseTree extends PreOrderTree, InClause {
+    final override predicate propagatesAbnormal(AstNode child) {
+      child = this.getPattern() or
+      child = this.getCondition()
+    }
+
+    private predicate lastCondition(AstNode last, BooleanCompletion c, boolean flag) {
+      last(this.getCondition(), last, c) and
+      (
+        flag = true and this.hasIfCondition()
+        or
+        flag = false and this.hasUnlessCondition()
+      )
+    }
+
+    final override predicate last(AstNode last, Completion c) {
+      last(this.getPattern(), last, c) and
+      c.(MatchingCompletion).getValue() = false
+      or
+      exists(BooleanCompletion bc, boolean flag, MatchingCompletion mc |
+        lastCondition(last, bc, flag) and
+        c =
+          any(NestedMatchingCompletion nmc |
+            nmc.getInnerCompletion() = bc and nmc.getOuterCompletion() = mc
+          )
+      |
+        mc.getValue() = false and
+        bc.getValue() = flag.booleanNot()
+        or
+        not exists(this.getBody()) and
+        mc.getValue() = true and
+        bc.getValue() = flag
+      )
+      or
+      last(this.getBody(), last, c)
+      or
+      not exists(this.getBody()) and
+      not exists(this.getCondition()) and
+      last(this.getPattern(), last, c)
+    }
+
+    final override predicate succ(AstNode pred, AstNode succ, Completion c) {
+      pred = this and
+      first(this.getPattern(), succ) and
+      c instanceof SimpleCompletion
+      or
+      exists(Expr next |
+        last(this.getPattern(), pred, c) and
+        c.(MatchingCompletion).getValue() = true and
+        first(next, succ)
+      |
+        next = this.getCondition()
+        or
+        not exists(this.getCondition()) and next = this.getBody()
+      )
+      or
+      exists(boolean flag |
+        lastCondition(pred, c, flag) and
+        c.(BooleanCompletion).getValue() = flag and
+        first(this.getBody(), succ)
+      )
+    }
+  }
+
  private class CharacterTree extends LeafTree, CharacterLiteral { }

  private class ClassDeclarationTree extends NamespaceTree, ClassDeclaration {
@@ -542,7 +923,8 @@ module Trees {
        c instanceof SimpleCompletion
        or
        this.hasDefaultValue() and
-        c.(MatchingCompletion).getValue() = true
+        c.(MatchingCompletion).getValue() = true and
+        c.isValidFor(this)
      )
    }

--- a/ruby/ql/test/library-tests/ast/Ast.expected
+++ b/ruby/ql/test/library-tests/ast/Ast.expected
@@ -864,6 +864,7 @@ control/cases.rb:
 #   67|       getPattern: [ArrayPattern] [ ..., * ]
 #   68|     getBranch: [InClause] in ... then ...
 #   68|       getPattern: [ArrayPattern] [ ..., * ]
+#   68|         getRestVariableAccess: [LocalVariableAccess] x
 #   68|         getSuffixElement: [IntegerLiteral] 3
 #   68|         getSuffixElement: [IntegerLiteral] 4
 #   69|     getBranch: [InClause] in ... then ...
--- a/ruby/ql/test/library-tests/ast/CONSISTENCY/CfgConsistency.expected
+++ b/ruby/ql/test/library-tests/ast/CONSISTENCY/CfgConsistency.expected
@@ -1,4 +0,0 @@
-deadEnd
-| control/cases.rb:19:13:19:19 | then ... |
-| control/cases.rb:20:13:20:19 | then ... |
-| control/cases.rb:21:13:21:19 | then ... |
--- a/ruby/ql/test/library-tests/ast/ValueText.expected
+++ b/ruby/ql/test/library-tests/ast/ValueText.expected
@@ -156,8 +156,8 @@
 | control/cases.rb:65:13:65:13 | 3 | 3 |
 | control/cases.rb:66:7:66:7 | 1 | 1 |
 | control/cases.rb:66:14:66:14 | 3 | 3 |
-| control/cases.rb:68:10:68:10 | 3 | 3 |
-| control/cases.rb:68:13:68:13 | 4 | 4 |
+| control/cases.rb:68:11:68:11 | 3 | 3 |
+| control/cases.rb:68:14:68:14 | 4 | 4 |
 | control/cases.rb:69:10:69:10 | 3 | 3 |
 | control/cases.rb:70:11:70:11 | 3 | 3 |
 | control/cases.rb:71:7:71:7 | :a | a |
@@ -176,6 +176,7 @@
 | control/cases.rb:76:13:76:13 | :b | b |
 | control/cases.rb:84:7:84:8 | 42 | 42 |
 | control/cases.rb:87:6:87:6 | 5 | 5 |
+| control/cases.rb:88:7:88:9 | foo | 42 |
 | control/cases.rb:90:6:90:13 | "string" | string |
 | control/cases.rb:91:9:91:11 | "foo" | foo |
 | control/cases.rb:91:13:91:15 | "bar" | bar |
--- a/ruby/ql/test/library-tests/ast/control/CONSISTENCY/CfgConsistency.expected
+++ b/ruby/ql/test/library-tests/ast/control/CONSISTENCY/CfgConsistency.expected
@@ -1,4 +0,0 @@
-deadEnd
-| cases.rb:19:13:19:19 | then ... |
-| cases.rb:20:13:20:19 | then ... |
-| cases.rb:21:13:21:19 | then ... |
--- a/ruby/ql/test/library-tests/ast/control/CaseExpr.expected
+++ b/ruby/ql/test/library-tests/ast/control/CaseExpr.expected
@@ -67,7 +67,7 @@ caseAllBranches
 | cases.rb:39:1:80:3 | case ... | 25 | cases.rb:65:3:65:18 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 26 | cases.rb:66:3:66:16 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 27 | cases.rb:67:3:67:9 | in ... then ... |
-| cases.rb:39:1:80:3 | case ... | 28 | cases.rb:68:3:68:15 | in ... then ... |
+| cases.rb:39:1:80:3 | case ... | 28 | cases.rb:68:3:68:16 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 29 | cases.rb:69:3:69:15 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 30 | cases.rb:70:3:70:17 | in ... then ... |
 | cases.rb:39:1:80:3 | case ... | 31 | cases.rb:71:3:71:10 | in ... then ... |
--- a/ruby/ql/test/library-tests/ast/control/cases.rb
+++ b/ruby/ql/test/library-tests/ast/control/cases.rb
@@ -65,7 +65,7 @@ case expr
  in [1, 2, 3, *] 
  in [1, *x, 3] 
  in [*] 
-  in [*, 3, 4] 
+  in [*x, 3, 4] 
  in [*, 3, *] 
  in [*a, 3, *b] 
  in {a:} 
--- a/ruby/ql/test/library-tests/controlflow/graph/Cfg.expected
+++ b/ruby/ql/test/library-tests/controlflow/graph/Cfg.expected
@@ -492,7 +492,7 @@ case.rb:
 #-----|  -> if_in_case

 #    1| if_in_case
-#-----|  -> exit case.rb (normal)
+#-----|  -> case_match

 #    1| exit if_in_case

@@ -567,6 +567,795 @@ case.rb:
 #    4| "2"
 #-----|  -> call to puts

+#    8| enter case_match
+#-----|  -> value
+
+#    8| case_match
+#-----|  -> case_match_no_match
+
+#    8| exit case_match
+
+#    8| exit case_match (normal)
+#-----|  -> exit case_match
+
+#    8| value
+#-----|  -> case ...
+
+#    9| case ...
+#-----|  -> value
+
+#    9| value
+#-----|  -> in ... then ...
+
+#   10| in ... then ...
+#-----|  -> 0
+
+#   10| 0
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match (normal)
+
+#   11| in ... then ...
+#-----|  -> 1
+
+#   11| 1
+#-----| no-match -> in ... then ...
+#-----| match -> 3
+
+#   11| then ...
+#-----|  -> exit case_match (normal)
+
+#   11| 3
+#-----|  -> then ...
+
+#   12| in ... then ...
+#-----|  -> 2
+
+#   12| 2
+#-----| no-match -> in ... then ...
+#-----| match -> 4
+
+#   12| then ...
+#-----|  -> exit case_match (normal)
+
+#   13| 4
+#-----|  -> then ...
+
+#   14| in ... then ...
+#-----|  -> x
+
+#   14| x
+#-----| match -> x
+
+#   14| ... == ...
+#-----| false -> in ... then ...
+#-----| true -> 6
+
+#   14| x
+#-----|  -> 5
+
+#   14| 5
+#-----|  -> ... == ...
+
+#   14| then ...
+#-----|  -> exit case_match (normal)
+
+#   14| 6
+#-----|  -> then ...
+
+#   15| in ... then ...
+#-----|  -> x
+
+#   15| x
+#-----| match -> x
+
+#   15| ... < ...
+#-----| false -> 7
+#-----| true -> 8
+
+#   15| x
+#-----|  -> 0
+
+#   15| 0
+#-----|  -> ... < ...
+
+#   15| then ...
+#-----|  -> exit case_match (normal)
+
+#   15| 7
+#-----|  -> then ...
+
+#   16| else ...
+#-----|  -> exit case_match (normal)
+
+#   16| 8
+#-----|  -> else ...
+
+#   20| enter case_match_no_match
+#-----|  -> value
+
+#   20| case_match_no_match
+#-----|  -> case_match_raise
+
+#   20| exit case_match_no_match
+
+#   20| exit case_match_no_match (abnormal)
+#-----|  -> exit case_match_no_match
+
+#   20| exit case_match_no_match (normal)
+#-----|  -> exit case_match_no_match
+
+#   20| value
+#-----|  -> case ...
+
+#   21| case ...
+#-----|  -> value
+
+#   21| value
+#-----|  -> in ... then ...
+
+#   22| in ... then ...
+#-----|  -> 1
+
+#   22| 1
+#-----| raise -> exit case_match_no_match (abnormal)
+#-----| match -> exit case_match_no_match (normal)
+
+#   26| enter case_match_raise
+#-----|  -> value
+
+#   26| case_match_raise
+#-----|  -> case_match_array
+
+#   26| exit case_match_raise
+
+#   26| exit case_match_raise (abnormal)
+#-----|  -> exit case_match_raise
+
+#   26| exit case_match_raise (normal)
+#-----|  -> exit case_match_raise
+
+#   26| value
+#-----|  -> case ...
+
+#   27| case ...
+#-----|  -> value
+
+#   27| value
+#-----|  -> in ... then ...
+
+#   28| in ... then ...
+#-----|  -> -> { ... }
+
+#   28| enter -> { ... }
+#-----|  -> x
+
+#   28| -> { ... }
+#-----| raise -> exit case_match_raise (abnormal)
+#-----| match -> exit case_match_raise (normal)
+
+#   28| exit -> { ... }
+
+#   28| exit -> { ... } (abnormal)
+#-----|  -> exit -> { ... }
+
+#   28| x
+#-----|  -> self
+
+#   28| call to raise
+#-----| raise -> exit -> { ... } (abnormal)
+
+#   28| self
+#-----|  -> "oops"
+
+#   28| "oops"
+#-----|  -> call to raise
+
+#   32| enter case_match_array
+#-----|  -> value
+
+#   32| case_match_array
+#-----|  -> case_match_find
+
+#   32| exit case_match_array
+
+#   32| exit case_match_array (abnormal)
+#-----|  -> exit case_match_array
+
+#   32| exit case_match_array (normal)
+#-----|  -> exit case_match_array
+
+#   32| value
+#-----|  -> case ...
+
+#   33| case ...
+#-----|  -> value
+
+#   33| value
+#-----|  -> in ... then ...
+
+#   34| in ... then ...
+#-----|  -> [ ..., * ]
+
+#   34| [ ..., * ]
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_array (normal)
+
+#   35| in ... then ...
+#-----|  -> [ ..., * ]
+
+#   35| [ ..., * ]
+#-----| no-match -> in ... then ...
+#-----| match -> x
+
+#   35| x
+#-----| match -> exit case_match_array (normal)
+
+#   36| in ... then ...
+#-----|  -> [ ..., * ]
+
+#   36| [ ..., * ]
+#-----| no-match -> in ... then ...
+#-----| match -> x
+
+#   36| x
+#-----| match -> exit case_match_array (normal)
+
+#   37| in ... then ...
+#-----|  -> Bar
+
+#   37| [ ..., * ]
+#-----| match -> a
+#-----| raise -> exit case_match_array (abnormal)
+
+#   37| Bar
+#-----| match -> [ ..., * ]
+#-----| raise -> exit case_match_array (abnormal)
+
+#   37| a
+#-----| match -> b
+
+#   37| b
+#-----| match -> c
+
+#   37| c
+#-----|  -> d
+
+#   37| d
+#-----| match -> e
+
+#   37| e
+#-----| match -> exit case_match_array (normal)
+
+#   41| enter case_match_find
+#-----|  -> value
+
+#   41| case_match_find
+#-----|  -> case_match_hash
+
+#   41| exit case_match_find
+
+#   41| exit case_match_find (abnormal)
+#-----|  -> exit case_match_find
+
+#   41| exit case_match_find (normal)
+#-----|  -> exit case_match_find
+
+#   41| value
+#-----|  -> case ...
+
+#   42| case ...
+#-----|  -> value
+
+#   42| value
+#-----|  -> in ... then ...
+
+#   43| in ... then ...
+#-----|  -> [ *,...,* ]
+
+#   43| [ *,...,* ]
+#-----| match -> x
+#-----| raise -> exit case_match_find (abnormal)
+
+#   43| x
+#-----|  -> 1
+
+#   43| 1
+#-----| match -> 2
+#-----| raise -> exit case_match_find (abnormal)
+
+#   43| 2
+#-----| match -> y
+#-----| raise -> exit case_match_find (abnormal)
+
+#   43| y
+#-----|  -> exit case_match_find (normal)
+
+#   47| enter case_match_hash
+#-----|  -> value
+
+#   47| case_match_hash
+#-----|  -> case_match_variable
+
+#   47| exit case_match_hash
+
+#   47| exit case_match_hash (abnormal)
+#-----|  -> exit case_match_hash
+
+#   47| exit case_match_hash (normal)
+#-----|  -> exit case_match_hash
+
+#   47| value
+#-----|  -> case ...
+
+#   48| case ...
+#-----|  -> value
+
+#   48| value
+#-----|  -> in ... then ...
+
+#   49| in ... then ...
+#-----|  -> Foo
+
+#   49| { ..., ** }
+#-----| no-match -> in ... then ...
+#-----| match -> 1
+
+#   49| Foo
+#-----|  -> Bar
+
+#   49| Bar
+#-----| match -> { ..., ** }
+#-----| no-match -> in ... then ...
+
+#   49| 1
+#-----| no-match -> in ... then ...
+#-----| match -> rest
+
+#   49| rest
+#-----|  -> exit case_match_hash (normal)
+
+#   50| in ... then ...
+#-----|  -> Bar
+
+#   50| { ..., ** }
+#-----| no-match -> in ... then ...
+#-----| match -> 1
+
+#   50| Bar
+#-----| match -> { ..., ** }
+#-----| no-match -> in ... then ...
+
+#   50| 1
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_hash (normal)
+
+#   51| in ... then ...
+#-----|  -> Bar
+
+#   51| { ..., ** }
+#-----| raise -> exit case_match_hash (abnormal)
+#-----| match -> exit case_match_hash (normal)
+
+#   51| Bar
+#-----| match -> { ..., ** }
+#-----| raise -> exit case_match_hash (abnormal)
+
+#   55| enter case_match_variable
+#-----|  -> value
+
+#   55| case_match_variable
+#-----|  -> case_match_underscore
+
+#   55| exit case_match_variable
+
+#   55| exit case_match_variable (normal)
+#-----|  -> exit case_match_variable
+
+#   55| value
+#-----|  -> case ...
+
+#   56| case ...
+#-----|  -> value
+
+#   56| value
+#-----|  -> in ... then ...
+
+#   57| in ... then ...
+#-----|  -> 5
+
+#   57| 5
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_variable (normal)
+
+#   58| in ... then ...
+#-----|  -> var
+
+#   58| var
+#-----| match -> exit case_match_variable (normal)
+
+#   63| enter case_match_underscore
+#-----|  -> value
+
+#   63| case_match_underscore
+#-----|  -> case_match_various
+
+#   63| exit case_match_underscore
+
+#   63| exit case_match_underscore (normal)
+#-----|  -> exit case_match_underscore
+
+#   63| value
+#-----|  -> case ...
+
+#   64| case ...
+#-----|  -> value
+
+#   64| value
+#-----|  -> in ... then ...
+
+#   65| in ... then ...
+#-----|  -> ... | ...
+
+#   65| ... | ...
+#-----|  -> 5
+
+#   65| 5
+#-----| no-match -> _
+#-----| match -> exit case_match_underscore (normal)
+
+#   65| _
+#-----| match -> exit case_match_underscore (normal)
+
+#   69| enter case_match_various
+#-----|  -> value
+
+#   69| case_match_various
+#-----|  -> case_match_guard_no_else
+
+#   69| exit case_match_various
+
+#   69| exit case_match_various (abnormal)
+#-----|  -> exit case_match_various
+
+#   69| exit case_match_various (normal)
+#-----|  -> exit case_match_various
+
+#   69| value
+#-----|  -> foo
+
+#   70| ... = ...
+#-----|  -> case ...
+
+#   70| foo
+#-----|  -> 42
+
+#   70| 42
+#-----|  -> ... = ...
+
+#   72| case ...
+#-----|  -> value
+
+#   72| value
+#-----|  -> in ... then ...
+
+#   73| in ... then ...
+#-----|  -> 5
+
+#   73| 5
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   74| in ... then ...
+#-----|  -> ^...
+
+#   74| ^...
+#-----|  -> foo
+
+#   74| foo
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   75| in ... then ...
+#-----|  -> "string"
+
+#   75| "string"
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   76| in ... then ...
+#-----|  -> Array
+
+#   76| call to []
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   76| Array
+#-----|  -> "foo"
+
+#   76| "foo"
+#-----|  -> "bar"
+
+#   76| "bar"
+#-----|  -> call to []
+
+#   77| in ... then ...
+#-----|  -> Array
+
+#   77| call to []
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   77| Array
+#-----|  -> :"foo"
+
+#   77| :"foo"
+#-----|  -> :"bar"
+
+#   77| :"bar"
+#-----|  -> call to []
+
+#   78| in ... then ...
+#-----|  -> /.*abc[0-9]/
+
+#   78| /.*abc[0-9]/
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   79| in ... then ...
+#-----|  -> 5
+
+#   79| 5
+#-----|  -> 10
+
+#   79| _ .. _
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   79| 10
+#-----|  -> _ .. _
+
+#   80| in ... then ...
+#-----|  -> 10
+
+#   80| _ .. _
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   80| 10
+#-----|  -> _ .. _
+
+#   81| in ... then ...
+#-----|  -> 5
+
+#   81| 5
+#-----|  -> _ .. _
+
+#   81| _ .. _
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   82| in ... then ...
+#-----|  -> ... => ...
+
+#   82| ... => ...
+#-----|  -> 5
+
+#   82| 5
+#-----| no-match -> in ... then ...
+#-----| match -> x
+
+#   82| x
+#-----|  -> exit case_match_various (normal)
+
+#   83| in ... then ...
+#-----|  -> ... | ...
+
+#   83| ... | ...
+#-----|  -> 5
+
+#   83| 5
+#-----| no-match -> ^...
+#-----| match -> exit case_match_various (normal)
+
+#   83| ^...
+#-----|  -> foo
+
+#   83| foo
+#-----| no-match -> "string"
+#-----| match -> exit case_match_various (normal)
+
+#   83| "string"
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   84| in ... then ...
+#-----|  -> Foo
+
+#   84| Bar
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   84| Foo
+#-----|  -> Bar
+
+#   85| in ... then ...
+#-----|  -> -> { ... }
+
+#   85| enter -> { ... }
+#-----|  -> x
+
+#   85| -> { ... }
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   85| exit -> { ... }
+
+#   85| exit -> { ... } (normal)
+#-----|  -> exit -> { ... }
+
+#   85| x
+#-----|  -> x
+
+#   85| ... == ...
+#-----|  -> exit -> { ... } (normal)
+
+#   85| x
+#-----|  -> 10
+
+#   85| 10
+#-----|  -> ... == ...
+
+#   86| in ... then ...
+#-----|  -> :foo
+
+#   86| :foo
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   87| in ... then ...
+#-----|  -> :"foo bar"
+
+#   87| :"foo bar"
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   88| in ... then ...
+#-----|  -> ... | ...
+
+#   88| ... | ...
+#-----|  -> 5
+
+#   88| - ...
+#-----| no-match -> 10
+#-----| match -> exit case_match_various (normal)
+
+#   88| 5
+#-----|  -> - ...
+
+#   88| + ...
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   88| 10
+#-----|  -> + ...
+
+#   89| in ... then ...
+#-----|  -> ... | ...
+
+#   89| ... | ...
+#-----|  -> nil
+
+#   89| nil
+#-----| no-match -> self
+#-----| match -> exit case_match_various (normal)
+
+#   89| self
+#-----| no-match -> true
+#-----| match -> exit case_match_various (normal)
+
+#   89| true
+#-----| no-match -> false
+#-----| match -> exit case_match_various (normal)
+
+#   89| false
+#-----| no-match -> __LINE__
+#-----| match -> exit case_match_various (normal)
+
+#   89| __LINE__
+#-----| no-match -> __FILE__
+#-----| match -> exit case_match_various (normal)
+
+#   89| __FILE__
+#-----| no-match -> __ENCODING__
+#-----| match -> exit case_match_various (normal)
+
+#   89| __ENCODING__
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   90| in ... then ...
+#-----|  -> ( ... )
+
+#   90| ( ... )
+#-----|  -> 1
+
+#   90| 1
+#-----|  -> _ .. _
+
+#   90| _ .. _
+#-----| no-match -> in ... then ...
+#-----| match -> exit case_match_various (normal)
+
+#   91| in ... then ...
+#-----|  -> ( ... )
+
+#   91| ( ... )
+#-----|  -> ... | ...
+
+#   91| ... | ...
+#-----|  -> 0
+
+#   91| 0
+#-----| no-match -> ""
+#-----| match -> exit case_match_various (normal)
+
+#   91| ""
+#-----| no-match -> [ ..., * ]
+#-----| match -> exit case_match_various (normal)
+
+#   91| [ ..., * ]
+#-----| no-match -> { ..., ** }
+#-----| match -> exit case_match_various (normal)
+
+#   91| { ..., ** }
+#-----| raise -> exit case_match_various (abnormal)
+#-----| match -> exit case_match_various (normal)
+
+#   95| enter case_match_guard_no_else
+#-----|  -> value
+
+#   95| case_match_guard_no_else
+#-----|  -> exit case.rb (normal)
+
+#   95| exit case_match_guard_no_else
+
+#   95| exit case_match_guard_no_else (abnormal)
+#-----|  -> exit case_match_guard_no_else
+
+#   95| exit case_match_guard_no_else (normal)
+#-----|  -> exit case_match_guard_no_else
+
+#   95| value
+#-----|  -> case ...
+
+#   96| case ...
+#-----|  -> value
+
+#   96| value
+#-----|  -> in ... then ...
+
+#   97| in ... then ...
+#-----|  -> x
+
+#   97| x
+#-----| match -> x
+
+#   97| ... == ...
+#-----| true -> 6
+#-----| raise -> exit case_match_guard_no_else (abnormal)
+
+#   97| x
+#-----|  -> 5
+
+#   97| 5
+#-----|  -> ... == ...
+
+#   97| then ...
+#-----|  -> exit case_match_guard_no_else (normal)
+
+#   97| 6
+#-----|  -> then ...
+
 cfg.html.erb:
 #    5| enter cfg.html.erb
 #-----|  -> @title
--- a/ruby/ql/test/library-tests/controlflow/graph/Nodes.expected
+++ b/ruby/ql/test/library-tests/controlflow/graph/Nodes.expected
@@ -9,6 +9,8 @@ callsWithNoArguments
 | break_ensure.rb:29:8:29:13 | call to nil? |
 | case.rb:2:8:2:9 | call to x1 |
 | case.rb:3:21:3:22 | call to x2 |
+| case.rb:88:8:88:9 | - ... |
+| case.rb:88:13:88:15 | + ... |
 | cfg.html.erb:12:24:12:24 | call to a |
 | cfg.html.erb:15:32:15:32 | call to a |
 | cfg.html.erb:16:32:16:32 | call to b |
@@ -80,6 +82,15 @@ positionalArguments
 | break_ensure.rb:51:10:51:14 | [ensure: raise] ... > ... | break_ensure.rb:51:14:51:14 | [ensure: raise] 0 |
 | case.rb:3:29:3:37 | call to puts | case.rb:3:34:3:37 | "x2" |
 | case.rb:4:17:4:24 | call to puts | case.rb:4:22:4:24 | "2" |
+| case.rb:14:13:14:18 | ... == ... | case.rb:14:18:14:18 | 5 |
+| case.rb:15:17:15:21 | ... < ... | case.rb:15:21:15:21 | 0 |
+| case.rb:28:14:28:25 | call to raise | case.rb:28:20:28:25 | "oops" |
+| case.rb:76:8:76:18 | call to [] | case.rb:76:11:76:13 | "foo" |
+| case.rb:76:8:76:18 | call to [] | case.rb:76:15:76:17 | "bar" |
+| case.rb:77:8:77:18 | call to [] | case.rb:77:11:77:13 | :"foo" |
+| case.rb:77:8:77:18 | call to [] | case.rb:77:15:77:17 | :"bar" |
+| case.rb:85:15:85:21 | ... == ... | case.rb:85:20:85:21 | 10 |
+| case.rb:97:13:97:18 | ... == ... | case.rb:97:18:97:18 | 5 |
 | cfg.html.erb:6:9:6:58 | call to stylesheet_link_tag | cfg.html.erb:6:29:6:41 | "application" |
 | cfg.html.erb:6:9:6:58 | call to stylesheet_link_tag | cfg.html.erb:6:44:6:58 | Pair |
 | cfg.html.erb:12:11:12:33 | call to link_to | cfg.html.erb:12:19:12:21 | "A" |
--- a/ruby/ql/test/library-tests/controlflow/graph/case.rb
+++ b/ruby/ql/test/library-tests/controlflow/graph/case.rb
@@ -4,3 +4,96 @@ def if_in_case
    when 2 then puts "2"
  end
 end
+
+def case_match value
+  case value
+    in 0 
+    in 1 then 3
+    in 2
+      4
+    in x if x == 5 then 6
+    in x unless x < 0 then 7
+    else 8
+  end
+end
+
+def case_match_no_match value
+  case value
+    in 1
+  end
+end
+
+def case_match_raise value
+  case value
+   in -> x { raise "oops"  }
+  end
+end
+
+def case_match_array value
+  case value
+    in [];
+    in [x];
+    in [x, ];
+    in Bar(a, b, *c, d, e);
+  end
+end
+
+def case_match_find value
+  case value 
+    in [*x, 1, 2, *y];
+  end
+end
+
+def case_match_hash value
+  case value
+    in Foo::Bar[ x:1, a:, **rest ];
+    in Bar( a: 1, **nil);
+    in Bar( ** );
+  end
+end
+
+def case_match_variable value
+  case value 
+    in 5
+    in var
+    in "unreachable"
+  end
+end
+
+def case_match_underscore value
+  case value 
+    in 5 | _ | "unreachable"
+  end
+end
+
+def case_match_various value
+  foo = 42
+
+  case value 
+    in 5
+    in ^foo
+    in "string"
+    in %w(foo bar)
+    in %i(foo bar)
+    in /.*abc[0-9]/
+    in 5 .. 10
+    in .. 10
+    in 5 ..
+    in 5 => x
+    in 5 | ^foo | "string"
+    in ::Foo::Bar
+    in -> x { x == 10 }
+    in :foo
+    in :"foo bar"
+    in -5 | +10
+    in nil | self | true | false | __LINE__ | __FILE__ | __ENCODING__
+    in (1 ..)
+    in (0 | "" | [] | {})
+  end
+end
+
+def case_match_guard_no_else value
+  case value
+    in x if x == 5 then 6
+  end
+end