JS: Model consolidate and factor in template syntax from call site

javascript/ql/src/semmle/javascript/frameworks/Templating.qll

@@ -190,6 +190,15 @@ module Templating {
     TemplateFile getTemplateFile() {
       result = getTemplateFileNode().(TemplateFileReference).getTemplateFile()
     }
+
+    /**
+     * Gets the template syntax used by this template instantiation, if known.
+     *
+     * If not known, the relevant syntax will be determined by a heuristic.
+     */
+    TemplateSyntax getTemplateSyntax() {
+      result = range.getTemplateSyntax()
+    }
   }
 
   /** Companion module to the `TemplateInstantiation` class. */
@@ -206,6 +215,13 @@ module Templating {
 
       /** Gets a data flow node that refers to an object whose properties become variables in the template. */
       abstract DataFlow::Node getTemplateParamsNode();
+
+      /**
+       * Gets the template syntax used by this template instantiation, if known.
+       *
+       * If not known, the relevant syntax will be determined by a heuristic.
+       */
+      TemplateSyntax getTemplateSyntax() { none() }
     }
   }
 
@@ -558,12 +574,20 @@ module Templating {
     result = getTemplateSyntaxInFolder(f.getParentContainer())
   }
 
+  private TemplateSyntax getTemplateSyntaxFromInstantiation(TemplateFile file) {
+    result = any(TemplateInstantiaton inst | inst.getTemplateFile() = file).getTemplateSyntax()
+  }
+
   /**
    * Gets a template syntax likely to be used in the given file.
    */
   TemplateSyntax getLikelyTemplateSyntax(TemplateFile file) {
+    result = getTemplateSyntaxFromInstantiation(file)
+    or
+    not exists(getTemplateSyntaxFromInstantiation(file)) and
     result.getAFileExtension() = file.getExtension()
     or
+    not exists(getTemplateSyntaxFromInstantiation(file)) and
     not file.getExtension() = any(TemplateSyntax s).getAFileExtension() and
     result = getTemplateSyntaxInFolder(file.getParentContainer())
   }
@@ -656,4 +680,38 @@ module Templating {
       result = tag.getFile().getParentContainer()
     }
   }
+
+  /**
+   * A call to a member of the `consolidate` library, seen as a template instantiation.
+   */
+  private class ConsolidateCall extends TemplateInstantiaton::Range, API::CallNode {
+    string engine;
+
+    ConsolidateCall() {
+      this = API::moduleImport("consolidate").getMember(engine).getACall()
+    }
+
+    override TemplateSyntax getTemplateSyntax() {
+      result.getAPackageName() = engine
+    }
+
+    override DataFlow::SourceNode getOutput() {
+      result = getParameter([1, 2]).getParameter(1).getAnImmediateUse()
+      or
+      not exists(getParameter([1, 2]).getParameter(1)) and
+      result = this
+    }
+
+    override DataFlow::Node getTemplateFileNode() {
+      result = getArgument(0)
+    }
+
+    override DataFlow::Node getTemplateContentNode() {
+      none()
+    }
+
+    override DataFlow::Node getTemplateParamsNode() {
+      result = getArgument(1)
+    }
+  }
 }

javascript/ql/test/library-tests/frameworks/Templating/consolidate.js

@@ -0,0 +1,4 @@
+import * as consolidate from 'consolidate';
+
+consolidate.ejs('views/instantiated_as_ejs.html', { data: 123 }, (err, html) => {});
+consolidate.handlebars('views/instantiated_as_hbs.html', { data: 123 }, (err, html) => {});

javascript/ql/test/library-tests/frameworks/Templating/test.expected

@@ -0,0 +1,9 @@
+getTemplateInstantiationSyntax
+| consolidate.js:3:1:3:83 | consoli ...  => {}) | ejs |
+| consolidate.js:4:1:4:90 | consoli ...  => {}) | mustache |
+getLikelyTemplateSyntax
+| views/instantiated_as_ejs.html:0:0:0:0 | views/instantiated_as_ejs.html | ejs |
+| views/instantiated_as_hbs.html:0:0:0:0 | views/instantiated_as_hbs.html | mustache |
+xssSink
+| views/instantiated_as_ejs.html:4:9:4:23 | <%- xss_sink %> |
+| views/instantiated_as_hbs.html:7:9:7:24 | {{{ xss_sink }}} |

javascript/ql/test/library-tests/frameworks/Templating/test.ql

@@ -0,0 +1,14 @@
+import javascript
+import semmle.javascript.security.dataflow.Xss
+
+query Templating::TemplateSyntax getTemplateInstantiationSyntax(Templating::TemplateInstantiaton inst) {
+  result = inst.getTemplateSyntax()
+}
+
+query Templating::TemplateSyntax getLikelyTemplateSyntax(Templating::TemplateFile file) {
+  result = Templating::getLikelyTemplateSyntax(file)
+}
+
+query DomBasedXss::Sink xssSink() {
+  any()
+}

javascript/ql/test/library-tests/frameworks/Templating/views/instantiated_as_ejs.html

@@ -0,0 +1,9 @@
+<html>
+    <body>
+        <%= safe %>
+        <%- xss_sink %>
+
+        {{ safe }}
+        {{{ safe }}}
+    </body>
+</html>

javascript/ql/test/library-tests/frameworks/Templating/views/instantiated_as_hbs.html

@@ -0,0 +1,9 @@
+<html>
+    <body>
+        <%= safe %>
+        <%- safe %>
+
+        {{ safe }}
+        {{{ xss_sink }}}
+    </body>
+</html>