Add a script that can generate simple test cases for user-exposed JS builtins

tools/generate-builtins-tests.py

Index: tools/generate-builtins-tests.py
diff --git a/tools/generate-builtins-tests.py b/tools/generate-builtins-tests.py
new file mode 100755
index 0000000000000000000000000000000000000000..4e6961deb1adfefcb6be998e98fd60e431c2eb58
--- /dev/null
+++ b/tools/generate-builtins-tests.py
@@ -0,0 +1,158 @@
+#!/usr/bin/env python
+# Copyright 2014 the V8 project authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import json
+import optparse
+import os
+import random
+import shutil
+import subprocess
+import sys
+
+
+BLACKLIST = [
+  # Skip special d8 functions.
+  "load", "os", "print", "read", "readline", "quit"
+]
+
+
+def GetRandomObject():
+  return random.choice([
+    "0", "1", "2.5", "0x1000", "\"string\"", "{foo: \"bar\"}", "[1, 2, 3]",
+    "function() { return 0; }"
+  ])
+
+
+g_var_index = 0
+
+
+def GetVars(result, num, first = []):
+  global g_var_index
+  variables = []
+  for i in range(num):
+    variables.append("__v_%d" % g_var_index)
+    g_var_index += 1
+  for var in variables:
+    result.append("var %s = %s;" % (var, GetRandomObject()))
+  return ", ".join(first + variables)
+
+
+# Wraps |string| in try..catch.
+def TryCatch(result, string, exception_behavior = ""):
+  result.append("try { %s } catch(e) { %s }" % (string, exception_behavior))
+
+
+def BuildTests(function, full_name, options):
+  assert function["type"] == "function"
+  global g_var_index
+  g_var_index = 0
+  result = ["// AUTO-GENERATED BY tools/generate-builtins-tests.py.\n"]
+  result.append("// Function call test:")
+  length = function["length"]
+  TryCatch(result, "%s(%s);" % (full_name, GetVars(result, length)))
+
+  if "prototype" in function:
+    proto = function["prototype"]
+    result.append("\n// Constructor test:")
+    TryCatch(result,
+             "var recv = new %s(%s);" % (full_name, GetVars(result, length)),
+             "var recv = new Object();")
+
+    getters = []
+    methods = []
+    for prop in proto:
+      proto_property = proto[prop]
+      proto_property_type = proto_property["type"]
+      if proto_property_type == "getter":
+        getters.append(proto_property)
+        result.append("recv.__defineGetter__(\"%s\", "
+                      "function() { return %s; });" %
+                      (proto_property["name"], GetVars(result, 1)))
+      if proto_property_type == "number":
+        result.append("recv.__defineGetter__(\"%s\", "
+                      "function() { return %s; });" %
+                      (proto_property["name"], GetVars(result, 1)))
+      if proto_property_type == "function":
+        methods.append(proto_property)
+    if getters:
+      result.append("\n// Getter tests:")
+      for getter in getters:
+        result.append("print(recv.%s);" % getter["name"])
+    if methods:
+      result.append("\n// Method tests:")
+      for method in methods:
+        args = GetVars(result, method["length"], ["recv"])
+        call = "%s.prototype.%s.call(%s)" % (full_name, method["name"], args)
+        TryCatch(result, call)
+
+  filename = os.path.join(options.outdir, "%s.js" % (full_name))
+  with open(filename, "w") as f:
+    f.write("\n".join(result))
+    f.write("\n")
+
+
+def VisitObject(obj, path, options):
+  obj_type = obj["type"]
+  obj_name = "%s%s" % (path, obj["name"])
+  if obj_type == "function":
+    BuildTests(obj, obj_name, options)
+  if "properties" in obj:
+    for prop_name in obj["properties"]:
+      prop = obj["properties"][prop_name]
+      VisitObject(prop, "%s." % (obj_name), options)
+
+
+def ClearGeneratedFiles(options):
+  if os.path.exists(options.outdir):
+    shutil.rmtree(options.outdir)
+
+
+def GenerateTests(options):
+  ClearGeneratedFiles(options)  # Re-generate everything.
+  output = subprocess.check_output(
+      "%s %s" % (options.d8, options.script), shell=True).strip()
+  objects = json.loads(output)
+
+  os.makedirs(options.outdir)
+  for obj_name in objects:
+    if obj_name in BLACKLIST: continue
+    obj = objects[obj_name]
+    VisitObject(obj, "", options)
+
+
+def BuildOptions():
+  result = optparse.OptionParser()
+  result.add_option("--d8", help="d8 binary to use",
+                    default="out/ia32.release/d8")
+  result.add_option("--outdir", help="directory where to place generated tests",
+                    default="test/mjsunit/builtins-gen")
+  result.add_option("--script", help="builtins detector script to run in d8",
+                    default="tools/detect-builtins.js")
+  return result
+
+
+def Main():
+  parser = BuildOptions()
+  (options, args) = parser.parse_args()
+  if len(args) != 1 or args[0] == "help":
+    parser.print_help()
+    return 1
+  action = args[0]
+
+  if action == "generate":
+    GenerateTests(options)
+    return 0
+
+  if action == "clear":
+    ClearGeneratedFiles(options)
+    return 0
+
+  print("Unknown action: %s" % action)
+  parser.print_help()
+  return 1
+
+
+if __name__ == "__main__":
+  sys.exit(Main())