add unit tests

wscript

@@ -1,3 +1,6 @@
+import platform
+import re
+
 def options(opt):
     opt.load("compiler_cxx")
 
@@ -10,3 +13,17 @@ def build(bld):
         target = "jes",
         source = bld.path.ant_glob("src/**/*.cc"),
         cxxflags = ["-Wall", "-std=gnu++14"])
+    test_libs = []
+    if re.search(r'linux', platform.platform(), re.IGNORECASE):
+        test_libs += ["pthread"]
+    test_sources = bld.path.ant_glob("src/**/*.cc")
+    test_sources = [s for s in test_sources if not s.abspath().endswith("src/jes.cc")]
+    test_sources += bld.path.ant_glob("test/src/**/*.cc")
+    test_sources += ["gtest-1.7.0/src/gtest-all.cc",
+                     "gtest-1.7.0/src/gtest_main.cc"]
+    bld(features = "cxx cxxprogram",
+        target = "tests",
+        source = test_sources,
+        includes = ["gtest-1.7.0/include", "gtest-1.7.0", "src"],
+        lib = test_libs,
+        cxxflags = ["-Wall", "-std=gnu++14"])