Clever vs Savvy Part 2

This is part 2 of a presentation I gave to a company where I work as a software mentor. The talk is about software maintenance and code re-use. It is entitled: Clever vs Savvy. In part 2, I take a piece of code and refactor it 7 different ways to demonstrate the concepts of clever and savvy.

Transcript

The following transcript was automatically generated by an algorithm.

00:02 : this is me coming up with a fictitious
00:07 : code example small enough that hopefully
00:11 : you can digest in this session and I
00:16 : refactored it in eight different steps
00:19 : so this is step one where this is the
00:24 : screen implemented in angular it uses a
00:28 : rest service and it fetches the user
00:32 : using this send request method larger so
00:43 : every every request regardless of
00:45 : whether it's get or toast goes through
00:48 : this send requests so sending requests
00:50 : to the database to get all the users and
00:53 : this is how it tells the database I want
00:55 : the users and this is I'm posting the
00:59 : user so you you pass two additional
01:03 : parameters to post a user this is to
01:06 : save a new version of the user into the
01:08 : database or a new user into the database
01:11 : and this library this API looks like
01:17 : this you you send a get request to this
01:23 : URL this is coming from sweet datacom
01:26 : which is a fictitious data service that
01:31 : I created but I actually didn't create
01:33 : it I just it's fiction and to get the
01:39 : list of users you would send a request
01:42 : to this URL and then you get a data back
01:45 : in this format it'll have this property
01:48 : called users so you have to drill into
01:50 : the user's property to get the array of
01:53 : users like this but for companies to
01:59 : actually put the word company here in
02:01 : the URL and you the property now is
02:03 : instead companies instead of users
02:07 : so the first person who implemented this
02:12 : rest service this is what they did they
02:15 : make this request this just puts this
02:23 : send request can either get or post this
02:28 : is very heavily related to the three pig
02:31 : Three Little Pigs story as well I'm just
02:34 : realizing it you're you mentally you can
02:37 : also think about relate this to the
02:39 : three little pigs as well okay so so you
02:45 : can either get or post and put that by
02:47 : default it's get so you don't pass that
02:50 : in its get it's gonna get this stuff and
02:54 : here there's this if statement that says
02:57 : if what you're trying to get which was
03:00 : passing from here if you what you're
03:02 : trying to get is the user and if it's a
03:06 : get method it's actually gonna go into
03:09 : the users property in order to grab this
03:12 : array for you that's the bat users but
03:17 : if it's company it'll go into the
03:18 : company's property to grab that that
03:21 : company's array for you
03:24 : I'm sure you know which little pay this
03:28 : resembles at this point for people have
03:32 : to have seen that story there's also a
03:34 : vehicle a but but if that doesn't match
03:37 : any of these you just return the data as
03:40 : is curiously okay so this this is
03:45 : version one version two is I decided I
03:52 : just really don't like that if it
03:55 : doesn't match any of the ones that it
03:58 : handles it just returns to the data as
04:00 : this in my opinion if if you see that
04:04 : there's something you might potentially
04:06 : have miss you just just threw an
04:08 : exception if you didn't write the code
04:10 : to handle
04:11 : chase so that's that's what I recommend
04:13 : in our cases when you foresee that oh I
04:17 : have to handle all these cases but I
04:20 : can't do them all at once I'm just
04:23 : handling these cases for now you just
04:26 : have a else statement or something that
04:29 : tells you it's one of the other cases
04:31 : I'm gonna throw an error so that if
04:33 : there's a developer coming along hitting
04:35 : the cases that I haven't handled they'll
04:37 : get an error telling them no our code
04:42 : doesn't do that yet if you want it
04:44 : you're gonna have to write that code I
04:45 : didn't do it or you have you can call me
04:52 : okay instead of mysteriously returning
04:57 : something cryptic so so that's my first
05:02 : change my second change example three is
05:06 : as you probably have guessed I really
05:10 : hate this gigantic if statement here
05:14 : that's symptomatic of the moods pick
05:18 : when and you can you can see this
05:21 : growing because clearly we probably will
05:24 : have to handle more model types than
05:27 : just three and the more you add to the
05:30 : list the more ridiculous this is going
05:34 : to become so I decided to do away with
05:37 : this entire section of complex Ness
05:43 : it's instead of having a switcher
05:46 : basically you actually don't need to
05:49 : switch her if you're at the higher level
05:55 : of context where you have business savvy
05:59 : knowledge so that that's an insight now
06:03 : this is not how it should be this should
06:05 : have been that's so just go into that
06:12 : property yourself like right why are you
06:15 : doing well why are you making the
06:18 : central that why are you making the
06:21 : reusable piece of the code do this you
06:24 : have the context here just do it
06:27 : yourself there's no need
06:30 : so I just removed all this code that's
06:32 : just all it does is go into the right
06:35 : property based on what you passed and
06:37 : you do it yourself
06:43 : I think this is what this would be
06:47 : symptomatic of one of the other pics
06:51 : okay so here here it's like let's add
06:59 : some helper methods to help with that
07:02 : drilling down or the property so that
07:05 : instead of calling into just that very
07:08 : generic send request your calling in to
07:11 : get users and get companies and get
07:14 : vehicles and then you don't have to
07:15 : drill down to this property just just to
07:20 : free you up for of doing that it's I
07:24 : mean this not very high ROI to doing
07:27 : this but but yet you do get to write
07:32 : code like this to call it like call get
07:35 : users which is more intentional versus
07:39 : send request may be I don't know I don't
07:42 : know what you think about whether this
07:44 : is better or than this version it's more
07:49 : explicit yeah so that's the the next
07:53 : step that I changed oh one thing I want
07:59 : to say relating to the the rest service
08:03 : just let's just talk about the rest
08:05 : service where we would place the rest
08:07 : service in the quadrant yeah in in the
08:10 : first version example one we would
08:12 : definitely put it in the fourth quadrant
08:14 : here clever and savvy it has all this
08:18 : terminology that's the domain of the
08:22 : business like user company vehicle does
08:25 : business domain vocabulary there and we
08:30 : have it
08:32 : so the first savviness it's clever
08:36 : there's just a lot of content in here so
08:40 : reading through this will take more
08:41 : mental power it's not super super clever
08:44 : but it's I mean there's a lot of content
08:47 : which just just by having a lot of
08:50 : content increases the cleverness so at
08:53 : this point which quadrant does the rest
08:57 : service be all right remove that
08:59 : gigantic if statement here we'd best sit
09:05 : if you want it you you you do that
09:08 : yourself basically so we just removed
09:12 : that oh yeah so it's actually it's it's
09:19 : really reduced it initially it was here
09:22 : you're saying we moved it towards here
09:24 : it's still somewhat clever I would say
09:26 : so maybe like it's like around here
09:31 : moving in a Cartesian coordinate system
09:35 : okay so this one it has we actually
09:41 : brought back some savviness in just
09:44 : putting these helper methods here
09:48 : although it it doesn't hurt the
09:51 : cleverness so maybe it's like they moved
09:57 : it
10:03 : oh this one I actually whereas the
10:07 : previous case we just had one sin
10:10 : request that handle both gets in posts I
10:13 : decided to split it up into a gap and a
10:17 : post and so like so the get user will
10:22 : call into the get whereas the save user
10:24 : will call into the post that that's the
10:28 : only change and we actually didn't
10:30 : change the UI code at all we only change
10:33 : because the UI code was using these more
10:36 : savvy helper methods so we only changed
10:40 : the internals of the rest service and
10:42 : split the send request up into a get
10:47 : versus a post and actually there's quite
10:49 : a bit of duplication between these two
10:52 : so where do you think we have have we
10:55 : moved anywhere and just it's less clever
10:59 : so we've moved it up in terms savviness
11:02 : probably the same right so we sort of
11:04 : moved it back up a little bit
11:13 : it's clean left
11:17 : [Music]
11:18 : so it's done it's in so it's not so dumb
11:23 : that's all the way I'd say maybe maybe
11:27 : like okay so that that yeah very precise
11:36 : we gonna write some equations to
11:39 : calculate the exact number one thing I
11:43 : would mention is when I split this send
11:47 : request up into a get versus a post we
11:51 : did make it less clever by removing this
11:54 : if statement right because there's
11:58 : there's no need for the if statement to
12:00 : figure out whether we're posting or not
12:02 : posting and in general
12:07 : eliminating if statements have the
12:10 : effect of making code less clever yeah
12:14 : if you want to make a piece of code
12:16 : easier to read try to remove if
12:18 : statements if you remove a turn or eight
12:30 : you get two points
12:32 : I use this pluralize NPM module to
12:41 : figure out based on the name of the
12:43 : model to figure out the plural version
12:45 : of the name so that it automatically if
12:48 : you ask for users it you get the user
12:52 : string in here I can ultimately convert
12:55 : that to users because this PluralEyes
12:58 : package does that for me so what I'm
13:03 : saying if is it like plural is user
13:10 : it'll give you users and if you
13:13 : PluralEyes company you actually give you
13:19 : tonie's spelled the correct way that's
13:22 : magic
13:23 : and and yeah it doesn't actually exist
13:29 : we have access to the API developer we
13:33 : just tell them not to use the plural as
13:35 : far away so this is a piece of magic
13:38 : that I decided to bring in for some
13:41 : reason but for Chinese there's no change
13:49 : there's no s in Chinese that you would
13:52 : okay after this change like the user or
13:56 : not even the user like you there used to
13:58 : be this extra like that users here
14:01 : that's not needed anymore because I can
14:04 : do it for all the cases I don't even
14:07 : care if you're adding new models that I
14:09 : don't know about I am assuming this
14:12 : magical function will work for those
14:15 : cases as well until I'm wrong and then
14:18 : I'm screwed but I'm just gonna assume
14:21 : the API uses proper English
14:24 : pluralization that matches up with
14:28 : whatever this module is doing and I'm
14:31 : gonna assume that works if it doesn't
14:33 : then somebody has a hard time debugging
14:36 : this code so yeah let's update this plot
14:42 : let's let's update this plot where do we
14:46 : just go more clever unless I agree so we
14:52 : [Music]
15:00 : to build on ourselves the users it has
15:10 : these which still makes it savage which
15:12 : I'm gonna remove in the next step but I
15:19 : contract a contract that's a it's will
15:25 : increase the savviness because I mean
15:28 : increase the cleverness because the the
15:30 : module is very clever I didn't write it
15:33 : but but I know the internals of that
15:35 : function is very clever it just made it
15:37 : more clever for now right but then the
15:41 : next step I remove all those helper
15:43 : functions so I just decided you know
15:45 : what all this savviness I'm just gonna
15:47 : remove it so that when you call it it
15:50 : just called a generic get so now what
15:53 : what do you do here it's it's more
15:56 : ignorant now right yeah so you just
15:59 : moved it up in this direction and then
16:03 : oh this one I ordered was extract some
16:09 : of the common code between get and post
16:11 : into these two helper methods that's all
16:15 : I did
16:16 : so it used to there used to be a lot of
16:19 : duplication between these two ones I did
16:23 : the link spec thing basically I made the
16:25 : two helpers that both of them would use
16:28 : in where they have paths in common what
16:32 : does this do to the code give anything
16:36 : more clever because now it's requiring
16:42 : information like the code itself doesn't
16:44 : do very much other thing all it does was
16:46 : concatenate a URL string based off of
16:50 : string that's into it so it's pretty but
16:54 : why do I do you think it's a more clever
16:57 : about from the perspective of the
17:07 : newcomer to this code that's reading it
17:10 : for the first time well what what though
17:15 : is about the same you don't think when
17:23 : you're reading to you the methods but
17:24 : now you know it's the same phone same
17:26 : chunk of code because extracted it means
17:29 : you guys okay but sometimes there's I
17:32 : think that sometimes you do things that
17:39 : decrease the cleverness and one
17:41 : and increase the cleverness yes that's
17:44 : true I think how do we start extracting
17:47 : things so that all the clever you have
17:51 : to take a global song of the cleverness
17:54 : in everything whenever you extract a
17:57 : method the reader if he may be like what
18:01 : is this really doing and he has to
18:04 : scroat you over or jump click into it
18:07 : and then read this and then jump back
18:09 : and if he doesn't feel the need to do
18:13 : that then it would be easy but if he did
18:16 : feel the need to do that it might be
18:17 : harder you know I think that's something
18:35 : that helps make less clever is type
18:40 : script because sometimes I don't need to
18:41 : jump in and understand the thing you
18:44 : come the hover over the thing it'll tell
18:46 : you what's the input on what's the
18:48 : output right so it depends on also
18:55 : depends on the weather these these
18:58 : methods are named in a way that would
19:02 : induce the reader to want to drill in or
19:04 : not like if you named it so
19:07 : unambiguously and clear that he thinks
19:09 : yeah I understand what is trying to do
19:13 : I'm just gonna