JS: heuristically recognize x.spec.y and x.test.y as test files

javascript/ql/src/filters/ClassifyFiles.ql

@@ -61,7 +61,14 @@ private predicate looksLikeExterns(TopLevel tl) {
 predicate classify(File f, string category) {
   isGenerated(f.getATopLevel()) and category = "generated"
   or
-  exists(Test t | t.getFile() = f | category = "test")
+  (
+    exists(Test t | t.getFile() = f)
+    or
+    exists(string stemExt | stemExt = "test" or stemExt = "spec" |
+      f = getTestFile(any(File orig), stemExt)
+    )
+  ) and
+  category = "test"
   or
   (f.getATopLevel().isExterns() or looksLikeExterns(f.getATopLevel())) and
   category = "externs"

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

@@ -44,7 +44,7 @@ class BDDTest extends Test, @callexpr {
  * same directory as `f` which is named `<base>.<ext>`.
  */
 bindingset[stemExt]
-private File getTestFile(File f, string stemExt) {
+File getTestFile(File f, string stemExt) {
   result = f.getParentContainer().getFile(f.getStem() + "." + stemExt + "." + f.getExtension())
 }
 

javascript/ql/test/query-tests/filters/ClassifyFiles/ClassifyFiles.expected

@@ -7,6 +7,7 @@
 | etherpad.html:0:0:0:0 | etherpad.html | generated |
 | exported-data.js:0:0:0:0 | exported-data.js | generated |
 | htmltidy.html:0:0:0:0 | htmltidy.html | generated |
+| implementation.spec.js:0:0:0:0 | implementation.spec.js | test |
 | implementation.test.js:0:0:0:0 | implementation.test.js | test |
 | jison-lex.js:0:0:0:0 | jison-lex.js | generated |
 | jison.js:0:0:0:0 | jison.js | generated |