JS: Simplify call graph metric

javascript/ql/src/meta/analysis-quality/CallGraphQuality.qll

@@ -47,97 +47,6 @@ class RelevantFunction extends Function {
   }
 }
 
-/**
- * Holds if `name` is a the name of an external module.
- */
-predicate isExternalLibrary(string name) {
-  // Mentioned in package.json
-  any(Dependency dep).info(name, _) or
-  // Node.js built-in
-  name = "assert" or
-  name = "async_hooks" or
-  name = "child_process" or
-  name = "cluster" or
-  name = "crypto" or
-  name = "dns" or
-  name = "domain" or
-  name = "events" or
-  name = "fs" or
-  name = "http" or
-  name = "http2" or
-  name = "https" or
-  name = "inspector" or
-  name = "net" or
-  name = "os" or
-  name = "path" or
-  name = "perf_hooks" or
-  name = "process" or
-  name = "punycode" or
-  name = "querystring" or
-  name = "readline" or
-  name = "repl" or
-  name = "stream" or
-  name = "string_decoder" or
-  name = "timer" or
-  name = "tls" or
-  name = "trace_events" or
-  name = "tty" or
-  name = "dgram" or
-  name = "url" or
-  name = "util" or
-  name = "v8" or
-  name = "vm" or
-  name = "worker_threads" or
-  name = "zlib"
-}
-
-/**
- * Holds if the global variable `name` is defined externally.
- */
-predicate isExternalGlobal(string name) {
-  exists(ExternalGlobalDecl decl | decl.getName() = name)
-  or
-  exists(Dependency dep |
-    // If name is never assigned anywhere, and it coincides with a dependency,
-    // it's most likely coming from there.
-    dep.info(name, _) and
-    not exists(Assignment assign | assign.getLhs().(GlobalVarAccess).getName() = name)
-  )
-  or
-  name = "_"
-}
-
-/**
- * Gets a node that was derived from an import of `moduleName`.
- *
- * This is a rough approximation as it follows all property reads, invocations,
- * and callbacks, so some of these might refer to internal objects.
- *
- * Additionally, we don't recognize when a project imports another file in the
- * same project using its module name (for example import "vscode" from inside the vscode project).
- */
-SourceNode externalNode() {
-  exists(string moduleName |
-    result = moduleImport(moduleName) and
-    isExternalLibrary(moduleName)
-  )
-  or
-  exists(string name |
-    result = globalVarRef(name) and
-    isExternalGlobal(name)
-  )
-  or
-  result = DOM::domValueRef()
-  or
-  result = jquery()
-  or
-  result = externalNode().getAPropertyRead()
-  or
-  result = externalNode().getAnInvocation()
-  or
-  result = externalNode().(InvokeNode).getCallback(_).getParameter(_)
-}
-
 /**
  * Gets a data flow node that can be resolved to a function, usually a callback.
  *
@@ -192,49 +101,15 @@ class ResolvableCall extends RelevantInvoke {
   }
 }
 
-/**
- * A call site that is believed to call an external function.
- */
-class ExternalCall extends RelevantInvoke {
-  ExternalCall() {
-    not this instanceof ResolvableCall and // avoid double counting
-    (
-      // Call to modelled external library
-      this = externalNode()
-      or
-      // 'require' call or similar
-      this = moduleImport(_)
-      or
-      // Resolved to externs file
-      exists(this.(InvokeNode).getACallee(1))
-      or
-      // Modelled as taint step but isn't from an NPM module, for example, `substring` or `push`.
-      exists(TaintTracking::AdditionalTaintStep step |
-        step.step(_, this)
-        or
-        step.step(this.getAnArgument(), _)
-      )
-    )
-  }
-}
-
 /**
  * A call site that could not be resolved.
  */
 class UnresolvableCall extends RelevantInvoke {
   UnresolvableCall() {
-    not this instanceof ResolvableCall and
-    not this instanceof ExternalCall
+    not this instanceof ResolvableCall
   }
 }
 
-/**
- * A call that is believed to call a function within the same project.
- */
-class NonExternalCall extends RelevantInvoke {
-  NonExternalCall() { not this instanceof ExternalCall }
-}
-
 /**
  * A function with at least one call site.
  */