JS: extract getDefaultNode from DefaultRange

Author: Esben Sparre Andreasen

javascript/ql/src/semmle/javascript/AMD.qll

@@ -263,6 +263,13 @@ private class AmdDependencyImport extends Import {
     not exists(super.getImportedModule()) and
     result = resolveByAbsolutePath()
   }
+
+  override DataFlow::Node getDefaultNode() {
+    exists(Parameter param |
+      any(AmdModuleDefinition def).dependencyParameter(this, param) and
+      result = DataFlow::parameterNode(param)
+    )
+  }
 }
 
 /**

javascript/ql/src/semmle/javascript/ES2015Modules.qll

@@ -43,6 +43,22 @@ class ImportDeclaration extends Stmt, Import, @importdeclaration {
 
   /** Gets an import specifier of this import declaration. */
   ImportSpecifier getASpecifier() { result = getSpecifier(_) }
+
+  override DataFlow::Node getDefaultNode() {
+    // `import * as http from 'http'` or `import http from `http`'
+    exists(ImportSpecifier is |
+      is = getASpecifier() and
+      result = DataFlow::ssaDefinitionNode(SSA::definition(is))
+    |
+      is instanceof ImportNamespaceSpecifier and
+      count(getASpecifier()) = 1
+      or
+      is.getImportedName() = "default"
+    )
+    or
+    // `import { createServer } from 'http'`
+    result = DataFlow::destructuredModuleImportNode(this)
+  }
 }
 
 /** A literal path expression appearing in an `import` declaration. */

javascript/ql/src/semmle/javascript/Expr.qll

@@ -1562,6 +1562,8 @@ class DynamicImportExpr extends @dynamicimport, Expr, Import {
   override PathExpr getImportedPath() { result = getSource() }
 
   override Module getEnclosingModule() { result = getTopLevel() }
+
+  override DataFlow::Node getDefaultNode() { result = DataFlow::valueNode(this) }
 }
 
 /** A literal path expression appearing in a dynamic import. */

javascript/ql/src/semmle/javascript/Modules.qll

@@ -160,6 +160,11 @@ abstract class Import extends ASTNode {
       result = resolveFromTypeRoot()
     )
   }
+
+  /**
+   * Gets the data flow node that the default import of this import is available at.
+   */
+  abstract DataFlow::Node getDefaultNode();
 }
 
 /**

javascript/ql/src/semmle/javascript/NodeJS.qll

@@ -234,6 +234,8 @@ class Require extends CallExpr, Import {
           priority - (prioritiesPerCandidate() * r + numberOfExtensions() + 1))
     )
   }
+
+  override DataFlow::Node getDefaultNode() { result = DataFlow::valueNode(this) }
 }
 
 /** An argument to `require` or `require.resolve`, considered as a path expression. */

javascript/ql/src/semmle/javascript/TypeScript.qll

@@ -212,6 +212,8 @@ class ExternalModuleReference extends Expr, Import, @externalmodulereference {
   override ControlFlowNode getFirstControlFlowNode() {
     result = getExpression().getFirstControlFlowNode()
   }
+
+  override DataFlow::Node getDefaultNode() { result = DataFlow::valueNode(this) }
 }
 
 /** A literal path expression appearing in an external module reference. */

javascript/ql/src/semmle/javascript/dataflow/Nodes.qll

@@ -461,37 +461,9 @@ module ModuleImportNode {
     string path;
 
     DefaultRange() {
-      // `require("http")`
-      exists(Require req | req.getImportedPath().getValue() = path |
-        this = DataFlow::valueNode(req)
-      )
-      or
-      // `import http = require("http")`
-      exists(ExternalModuleReference req | req.getImportedPath().getValue() = path |
-        this = DataFlow::valueNode(req)
-      )
-      or
-      // `import * as http from 'http'` or `import http from `http`'
-      exists(ImportDeclaration id, ImportSpecifier is |
-        id.getImportedPath().getValue() = path and
-        is = id.getASpecifier() and
-        this = DataFlow::ssaDefinitionNode(SSA::definition(is))
-      |
-        is instanceof ImportNamespaceSpecifier and
-        count(id.getASpecifier()) = 1
-        or
-        is.getImportedName() = "default"
-      )
-      or
-      // `import { createServer } from 'http'`
-      exists(ImportDeclaration id |
-        this = DataFlow::destructuredModuleImportNode(id) and
-        id.getImportedPath().getValue() = path
-      )
-      or
-      // declared AMD dependency
-      exists(AmdModuleDefinition amd |
-        this = DataFlow::parameterNode(amd.getDependencyParameter(path))
+      exists(Import i |
+        this = i.getDefaultNode() and
+        i.getImportedPath().getValue() = path
       )
       or
       // AMD require