TEST: update example script update function

Author: Qinghao Shi

tools/test/examples/README.md

@@ -16,7 +16,7 @@ The scripts in this folder are used for testing `mbed-os` official examples. It
 
 * **deploy** - if the example directory exists as provided by the .json configuration file, pulls in the examples dependencies by using `mbed-cli deploy`.
 
-* **update** - for each example repo identified in the config .json object, updates the version of `mbed-os` to that specified by the supplied GitHub tag. This function assumes that each example repo has already been cloned.
+* **update** - for each example repo identified in the config .json object, updates the version of example to that specified by the supplied GitHub tag. This function assumes that each example repo has already been cloned.
 
 * **compile** - compiles combinations of example programs, targets and compile chains.
 

tools/test/examples/examples.py

@@ -165,8 +165,8 @@ def do_compile(args, config, examples):
     return failures 
 
 def do_update(args, config, examples):
-    """ Test update the mbed-os to the version specified by the tag """
-    return lib.update_mbedos_version(config, args.TAG, examples)
+    """ Test update the example to the version specified by the tag """
+    return lib.update_example_version(config, args.TAG, examples)
 
 def do_list(_, config, examples):
     """List the examples in the config file"""

tools/test/examples/examples_lib.py

@@ -438,25 +438,24 @@ def compile_repos(config, toolchains, targets, profiles, verbose, exp_filter, jo
     return results
 
 
-def update_mbedos_version(config, tag, exp_filter):
+def update_example_version(config, tag, exp_filter):
     """ For each example repo identified in the config json object, update the version of
-        mbed-os to that specified by the supplied GitHub tag. This function assumes that each
+        example to that specified by the supplied GitHub tag. This function assumes that each
         example repo has already been cloned.
 
     Args:
     config - the json object imported from the file.
     tag - GitHub tag corresponding to a version of mbed-os to upgrade to.
 
     """
-    print("\nUpdating mbed-os in examples to version '%s'\n" % tag)
+    print("\nUpdating example to version(branch) '%s'\n" % tag)
     for example in config['examples']:
         if example['name'] not in exp_filter:
             continue
         for name in get_sub_examples_list(example):
-            update_dir =  name + "/mbed-os"
-            os.chdir(update_dir)
+            os.chdir(name)
             logging.info("In folder '%s'" % name)
-            cmd = "mbed-cli update %s --clean" %tag
+            cmd = "git checkout -B %s origin/%s" %(tag, tag)
             logging.info("Executing command '%s'..." % cmd)
             result = subprocess.call(cmd, shell=True)
             os.chdir(CWD)