JavaScript: Remove omittable exists variables

javascript/ql/lib/semmle/javascript/DOM.qll

@@ -465,10 +465,7 @@ module DOM {
    */
   private DataFlow::SourceNode nonFirstLocationType(DataFlow::TypeTracker t) {
     // One step inlined in the beginning.
-    exists(DataFlow::TypeTracker t2 |
-      result =
-        any(DataFlow::Node n | n.hasUnderlyingType("Location")).getALocalSource().track(t2, t)
-    )
+    result = any(DataFlow::Node n | n.hasUnderlyingType("Location")).getALocalSource().track(_, t)
     or
     exists(DataFlow::TypeTracker t2 | result = nonFirstLocationType(t2).track(t2, t))
   }

javascript/ql/lib/semmle/javascript/DefUse.qll

@@ -302,7 +302,7 @@ deprecated private int nextDefAfter(BasicBlock bb, Variable v, int i, VarDef d)
  * DEPRECATED: Use the `SSA.qll` library instead.
  */
 deprecated predicate localDefinitionOverwrites(LocalVariable v, VarDef earlier, VarDef later) {
-  exists(BasicBlock bb, int i, int next | next = nextDefAfter(bb, v, i, earlier) |
+  exists(BasicBlock bb, int next | next = nextDefAfter(bb, v, _, earlier) |
     bb.defAt(next, v, later)
     or
     exists(BasicBlock succ | succ = bb.getASuccessor() |

javascript/ql/lib/semmle/javascript/Expr.qll

@@ -571,7 +571,7 @@ class ObjectExpr extends @obj_expr, Expr {
   Property getProperty(int i) { properties(result, this, i, _, _) }
 
   /** Gets a property in this object literal. */
-  Property getAProperty() { exists(int i | result = this.getProperty(i)) }
+  Property getAProperty() { result = this.getProperty(_) }
 
   /** Gets the number of properties in this object literal. */
   int getNumProperty() { result = count(this.getAProperty()) }

javascript/ql/lib/semmle/javascript/Functions.qll

@@ -47,7 +47,7 @@ class Function extends @function, Parameterized, TypeParameterized, StmtContaine
   }
 
   /** Gets a parameter of this function. */
-  override Parameter getAParameter() { exists(int idx | result = this.getParameter(idx)) }
+  override Parameter getAParameter() { result = this.getParameter(_) }
 
   /** Gets the parameter named `name` of this function, if any. */
   SimpleParameter getParameterByName(string name) {

javascript/ql/lib/semmle/javascript/NodeJS.qll

@@ -316,7 +316,7 @@ class Require extends CallExpr, Import {
   override Module resolveImportedPath() {
     moduleInFile(result, this.load(min(int prio | moduleInFile(_, this.load(prio)))))
     or
-    not exists(Module mod | moduleInFile(mod, this.load(_))) and
+    not moduleInFile(_, this.load(_)) and
     result = Import.super.resolveImportedPath()
   }
 

javascript/ql/lib/semmle/javascript/Routing.qll

@@ -723,7 +723,7 @@ module Routing {
     isInstalledAt(result, router, node)
     or
     result = getMostRecentRouteSetupAt(router, node.getAPredecessor()) and
-    not exists(RouteSetup setup | isInstalledAt(setup, router, node))
+    not isInstalledAt(_, router, node)
   }
 
   /**
@@ -977,8 +977,8 @@ module Routing {
    * Holds if `pred -> succ` is a data-flow step between access paths on request input objects.
    */
   private predicate middlewareDataFlowStep(DataFlow::Node pred, DataFlow::Node succ) {
-    exists(Node writer, Node reader, int n, string path |
-      potentialAccessPathStep(writer, pred, reader, succ, n, path) and
+    exists(Node writer, Node reader |
+      potentialAccessPathStep(writer, pred, reader, succ, _, _) and
       pragma[only_bind_out](reader).isGuardedByNode(pragma[only_bind_out](writer))
     )
     or

javascript/ql/lib/semmle/javascript/dataflow/Configuration.qll

@@ -1155,9 +1155,9 @@ private predicate parameterPropRead(
   DataFlow::Node arg, string prop, DataFlow::Node succ, DataFlow::Configuration cfg,
   PathSummary summary
 ) {
-  exists(Function f, DataFlow::Node read, DataFlow::Node invk, DataFlow::Node parm |
+  exists(Function f, DataFlow::Node read |
     reachesReturn(f, read, cfg, summary) and
-    parameterPropReadStep(parm, read, prop, cfg, arg, invk, f, succ)
+    parameterPropReadStep(_, read, prop, cfg, arg, _, f, succ)
   )
 }
 
@@ -1764,11 +1764,8 @@ private PathNode getASuccessor(PathNode nd) {
   result = initialMidNode(nd)
   or
   // mid node to mid node
-  exists(
-    Configuration cfg, DataFlow::Node predNd, PathSummary summary, DataFlow::Node succNd,
-    PathSummary newSummary
-  |
-    midNodeStep(nd, predNd, cfg, summary, succNd, newSummary) and
+  exists(Configuration cfg, PathSummary summary, DataFlow::Node succNd, PathSummary newSummary |
+    midNodeStep(nd, _, cfg, summary, succNd, newSummary) and
     result = MkMidNode(succNd, id(cfg), summary.append(newSummary))
   )
   or

javascript/ql/lib/semmle/javascript/dataflow/Portals.qll

@@ -196,18 +196,14 @@ private module NpmPackagePortal {
 
   /** Holds if `imp` is an import of package `pkgName`. */
   predicate imports(DataFlow::SourceNode imp, string pkgName) {
-    exists(NpmPackage pkg |
-      imp = getAModuleImport(pkg, pkgName) and
-      pkgName.regexpMatch("[^./].*")
-    )
+    imp = getAModuleImport(_, pkgName) and
+    pkgName.regexpMatch("[^./].*")
   }
 
   /** Holds if `imp` imports `member` from package `pkgName`. */
   predicate imports(DataFlow::SourceNode imp, string pkgName, string member) {
-    exists(NpmPackage pkg |
-      imp = getAModuleMemberImport(pkg, pkgName, member) and
-      pkgName.regexpMatch("[^./].*")
-    )
+    imp = getAModuleMemberImport(_, pkgName, member) and
+    pkgName.regexpMatch("[^./].*")
   }
 
   /** Gets the main module of package `pkgName`. */
@@ -404,7 +400,7 @@ private module InstancePortal {
    * right-hand side of that definition.
    */
   predicate instanceMemberDef(Portal base, string name, DataFlow::Node rhs, boolean escapes) {
-    exists(AbstractInstance i, DataFlow::SourceNode ctor | isInstance(base, ctor, i, escapes) |
+    exists(DataFlow::SourceNode ctor | isInstance(base, ctor, _, escapes) |
       // ES2015 instance method
       exists(MemberDefinition mem |
         mem = ctor.getAstNode().(ClassDefinition).getAMember() and

javascript/ql/lib/semmle/javascript/dataflow/TaintTracking.qll

@@ -611,9 +611,9 @@ module TaintTracking {
         )
         or
         // String.fromCharCode and String.fromCodePoint
-        exists(int i, DataFlow::MethodCallNode mcn |
+        exists(DataFlow::MethodCallNode mcn |
           mcn = succ and
-          pred = mcn.getArgument(i) and
+          pred = mcn.getAnArgument() and
           mcn.getMethodName() = ["fromCharCode", "fromCodePoint"]
         )
         or

javascript/ql/lib/semmle/javascript/dataflow/internal/AnalyzedParameters.qll

@@ -6,7 +6,7 @@ private import VariableTypeInference
  */
 pragma[nomagic]
 predicate isAnalyzedParameter(Parameter p) {
-  exists(FunctionWithAnalyzedParameters f, int parmIdx | p = f.getParameter(parmIdx) |
+  exists(FunctionWithAnalyzedParameters f | p = f.getAParameter() |
     // we cannot track flow into rest parameters
     not p.isRestParameter()
   )

javascript/ql/lib/semmle/javascript/dataflow/internal/InterModuleTypeInference.qll

@@ -82,9 +82,9 @@ private predicate relevantExport(ES2015Module m, string x) {
     x = id.getASpecifier().getImportedName()
   )
   or
-  exists(ReExportDeclaration rexp, string y |
+  exists(ReExportDeclaration rexp |
     rexp.getReExportedModule() = m and
-    reExportsAs(rexp, x, y)
+    reExportsAs(rexp, x, _)
   )
 }
 

javascript/ql/lib/semmle/javascript/frameworks/HTTP.qll

@@ -620,9 +620,7 @@ module Http {
             create.getArgument(0).asExpr() instanceof NullLiteral
           )
         ) and
-        exists(RouteHandlerCandidate candidate |
-          getAPossiblyDecoratedHandler(candidate).flowsTo(this.getAPropertyWrite().getRhs())
-        )
+        getAPossiblyDecoratedHandler(_).flowsTo(this.getAPropertyWrite().getRhs())
       }
 
       override DataFlow::SourceNode getRouteHandler(DataFlow::SourceNode access) {

javascript/ql/lib/semmle/javascript/frameworks/Handlebars.qll

@@ -130,17 +130,14 @@ private module HandlebarsTaintSteps {
    * ```
    */
   private predicate isHandlebarsArgStep(DataFlow::Node pred, DataFlow::Node succ) {
-    exists(
-      string helperName, DataFlow::CallNode templatingCall, DataFlow::CallNode compileCall,
-      DataFlow::FunctionNode func
-    |
+    exists(string helperName, DataFlow::CallNode templatingCall, DataFlow::CallNode compileCall |
       templatingCall = compiledTemplate(compileCall).getACall() and
       exists(string templateText, string paramName, int argIdx |
         compileCall.getArgument(0).mayHaveStringValue(templateText)
       |
         pred = templatingCall.getArgument(0).getALocalSource().getAPropertyWrite(paramName).getRhs() and
         isTemplateHelperCallArg(templateText, helperName, argIdx, paramName) and
-        succ = getRegisteredHelperParam(helperName, func, argIdx)
+        succ = getRegisteredHelperParam(helperName, _, argIdx)
       )
     )
   }

javascript/ql/lib/semmle/javascript/frameworks/PkgCloud.qll

@@ -35,8 +35,8 @@ module PkgCloud {
     string kind;
 
     Credentials() {
-      exists(string propertyName, DataFlow::InvokeNode invk, int i |
-        takesConfigurationObject(invk, i) and
+      exists(string propertyName, DataFlow::InvokeNode invk |
+        takesConfigurationObject(invk, _) and
         this = invk.getOptionArgument(0, propertyName)
       |
         /*