JS: Deprecate getAnExportedSymbol() and DubiousImport.ql

getAnExportedSymbol() has a complex implementation that I'd rather not want to migrate
given that it's only used by a dead query.

Author: asgerf

javascript/ql/integration-tests/query-suite/not_included_in_qls.expected

@@ -44,7 +44,6 @@ ql/javascript/ql/src/Metrics/FUseOfES6.ql
 ql/javascript/ql/src/Metrics/FunCyclomaticComplexity.ql
 ql/javascript/ql/src/Metrics/FunLinesOfCode.ql
 ql/javascript/ql/src/NodeJS/CyclicImport.ql
-ql/javascript/ql/src/NodeJS/DubiousImport.ql
 ql/javascript/ql/src/NodeJS/UnresolvableImport.ql
 ql/javascript/ql/src/NodeJS/UnusedDependency.ql
 ql/javascript/ql/src/Performance/NonLocalForIn.ql

javascript/ql/lib/semmle/javascript/Modules.qll

@@ -25,8 +25,8 @@ abstract class Module extends TopLevel {
   /** Gets a module from which this module imports. */
   Module getAnImportedModule() { result = this.getAnImport().getImportedModule() }
 
-  /** Gets a symbol exported by this module. */
-  string getAnExportedSymbol() { exists(this.getAnExportedValue(result)) }
+  /** DEPRECATED. Use `exists(getAnExportedValue(name))` instead. */
+  deprecated string getAnExportedSymbol() { exists(this.getAnExportedValue(result)) }
 
   /**
    * Get a value that is explicitly exported from this module with under `name`.

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

@@ -67,16 +67,6 @@ class NodeModule extends Module {
     result = this.getExportsSourceNode().getALocalUse()
   }
 
-  /** Gets a symbol exported by this module. */
-  override string getAnExportedSymbol() {
-    result = super.getAnExportedSymbol()
-    or
-    result = this.getAnImplicitlyExportedSymbol()
-    or
-    // getters and the like.
-    result = this.getExportsSourceNode().getAPropertyWrite().getPropertyName()
-  }
-
   override DataFlow::Node getAnExportedValue(string name) {
     // a property write whose base is `exports` or `module.exports`
     result = this.getExportsSourceNode().getAPropertyWrite(name).getRhs()
@@ -126,29 +116,6 @@ class NodeModule extends Module {
     )
   }
 
-  /** Gets a symbol that the module object inherits from its prototypes. */
-  private string getAnImplicitlyExportedSymbol() {
-    exists(ExternalConstructor ec | ec = this.getPrototypeOfExportedExpr() |
-      result = ec.getAMember().getName()
-      or
-      ec instanceof FunctionExternal and result = "prototype"
-      or
-      ec instanceof ArrayExternal and
-      exists(NumberLiteral nl | result = nl.getValue() and exists(result.toInt()))
-    )
-  }
-
-  /** Gets an externs declaration of the prototype object of a value exported by this module. */
-  private ExternalConstructor getPrototypeOfExportedExpr() {
-    exists(AbstractValue exported | exported = this.getAModuleExportsValue() |
-      result instanceof ObjectExternal
-      or
-      exported instanceof AbstractFunction and result instanceof FunctionExternal
-      or
-      exported instanceof AbstractOtherObject and result instanceof ArrayExternal
-    )
-  }
-
   deprecated override predicate searchRoot(PathExpr path, Folder searchRoot, int priority) {
     path.getEnclosingModule() = this and
     exists(string pathval | pathval = path.getValue() |
@@ -184,21 +151,6 @@ private DataFlow::SourceNode getASourceProp(DynamicPropertyAccess::EnumeratedPro
   )
 }
 
-/**
- * Gets an expression that syntactically could be a alias for `module.exports`.
- * This predicate exists to reduce the size of `getAModuleExportsNode`,
- * while keeping all the tuples that could be relevant in later computations.
- */
-pragma[noinline]
-private DataFlow::Node getAModuleExportsCandidate() {
-  // A bit of manual magic
-  result = any(DataFlow::PropWrite w).getBase()
-  or
-  result = DataFlow::valueNode(any(PropAccess p | exists(p.getPropertyName())).getBase())
-  or
-  result = DataFlow::valueNode(any(ObjectExpr obj))
-}
-
 /**
  * Holds if `nodeModules` is a folder of the form `<prefix>/node_modules`, where
  * `<prefix>` is a (not necessarily proper) prefix of `f` and does not end in `/node_modules`,

javascript/ql/src/NodeJS/DubiousImport.qhelp

@@ -1,11 +1,3 @@
-module_getAnExportedSymbol
-| b.js:1:1:8:0 | <toplevel> | sneaky |
-| d.js:1:1:7:15 | <toplevel> | baz |
-| reexport/a.js:1:1:3:1 | <toplevel> | foo |
-| reexport/b.js:1:1:6:1 | <toplevel> | bar |
-| reexport/b.js:1:1:6:1 | <toplevel> | foo |
-| sub/c.js:1:1:4:0 | <toplevel> | foo |
-| sub/f.js:1:1:4:17 | <toplevel> | bar |
 module_getAnImport
 | a.js:1:1:14:0 | <toplevel> | a.js:1:9:1:22 | require('./b') |
 | a.js:1:1:14:0 | <toplevel> | a.js:2:7:2:19 | require('fs') |

javascript/ql/src/NodeJS/DubiousImport.ql

@@ -1,9 +1,5 @@
 import javascript
 
-query predicate module_getAnExportedSymbol(NodeModule m, string symbol) {
-  symbol = m.getAnExportedSymbol()
-}
-
 query predicate module_getAnImport(NodeModule m, Import imp) { imp = m.getAnImport() }
 
 query predicate module_getAnImportedModule(NodeModule m, Module mod) {