How to check Clojure, macro specs?

See also questions close to this topic

• clojure/lein repl does not work with all database loaded

  I have used lien repl commond to test some operation on the database of my project. But I was not able to connect to it.

  Then I found that the issue is database was not getting loaded. The only solution i was able to try out was:

  lein run 
  

  this resulted in following messages:

  ---

  2018-04-24 12:23:07,397 [main] INFO  guestbook.core - #'guestbook.db.core/*db* started 
  2018-04-24 12:23:07,398 [main] INFO  guestbook.core - #'guestbook.handler/init-app started 
  2018-04-24 12:23:07,398 [main] INFO  guestbook.core - #'guestbook.handler/app started 
  2018-04-24 12:23:07,398 [main] INFO  guestbook.core - #'guestbook.core/http-server started 
  2018-04-24 12:23:07,398 [main] INFO  guestbook.core - #'guestbook.core/repl-server started 
  

  ---

  then I ran the following command :

  ---

  lein repl  :connect 7000
  
  this connected to database and started repl. next commands worked fine: 
  user=> (use 'guestbook.db.core)
  nil
  user=> (get-messages)
  nil
  

  ---

  Please let me know if there is any other way too?
• nginx prod setup for Clojure WebSocket app

  I'm trying to deploy my first Clojure WebSocket app and I think I'm getting close. I get a good response locally, and it looks like the endpoint wants to face the outside world (I see that the port is open when I run netstat), but no response. I'm certain that I have something setup incorrectly in nginx.

  I currently already host a few other websites on this server, just want to add the necessary config to get requests made to wss://domain.com:8001 to communicate with my app.

  Here is the location entry I'm using now:

  location / {
    proxy_pass http://localhost:8001;
    proxy_http_version 1.1;
    proxy_set_header Connection "";
    proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for;
    proxy_set_header Host $http_host;
    proxy_set_header X-Forwarded-Proto $scheme;
    proxy_redirect off;
    access_log /var/www/logs/test.access.log;
    error_log /var/www/logs/test.error.log;
  }
  

  Could anyone help point me in the right direction? My guess is that I actually have too much in the config, and what's there is probably not correct.

  ** EDIT: ** For interested parties, I put up my working config (based on Erik Dannenberg's answer) in a gist.
• Clojure app running only in tcp6

  So I'm in over my head, but I nearly have a working Clojure app with WebSocket connection deployed to a prod-like environment, but there are a few things that I can't seem to work out. When I hit the endpoint with curl from localhost I get the response I was hoping for, so far so good. But when I try access it from my domain, I don't get a connection. When I checked netstat to make sure the port (8001) is open, I see the following:

  Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name    
  tcp        0      0 0.0.0.0:80              0.0.0.0:*               LISTEN      3283/nginx: master  
  tcp        0      0 0.0.0.0:22              0.0.0.0:*               LISTEN      3218/sshd           
  tcp        0      0 0.0.0.0:443             0.0.0.0:*               LISTEN      3283/nginx: master  
  tcp6       0      0 :::8001                 :::*                    LISTEN      3260/java           
  tcp6       0      0 :::80                   :::*                    LISTEN      3283/nginx: master  
  tcp6       0      0 :::22                   :::*                    LISTEN      3218/sshd           
  tcp6       0      0 :::443                  :::*                    LISTEN      3283/nginx: master  
  

  I am running ufw but I already allowed the port, so I'm not sure if there is something I need to do when running the app to make it available as a normal tcp service? Or am I barking up the wrong tree?

  Here is the command that is currently running:

  java -jar test.jar 8001
  

  Also I was torn between here and serverfault, but opted for stackoverflow because I think it's Clojure-centric. Please feel free to correct me.
• C++: Can a macro argument have a space in it?

  If I define a macro taking argument as below.

  #define define_int(a) int a;
  

  And provide an argument with space in between like below

  define_int(* a)
  

  and get output?

  int * a;
  

  ---

  Intended use

  #define ASSIGN(A,B) B=A;
  

  I want to return from a function directly using this macro as

  ASSIGN(A, return B)
  

  so that it would output,

  return B = A;
  
• How to copy data from one sheet to another when modified in excel using macros

  Currently I am working in excel i need a vba script like whenever i modify a data a new sheet should generate with the modified username can some one help me on this?
• C macro function has the same output of equivalent normal function, but the algorithm has a different output

  So I've got a function that has the same definition as a macro function, and they output the same value. To confirm this, I did this:

  int a(int vertex, int offset) {
        int value = vertex*numberOfoffsets + offset;
        if (value != b(vertex, offset)) printf("error\n");
        return value;
  }
  

  Here's the macro:

  #define b(vertex, offset) (vertex*numberOfoffsets + offset)  //EDIT: I had mta instead of b here (on the stackoverflow post)
  

  Note that numberOfOffsets is also a macro itself, which returns 6. I ran the algorithm using a(vertex,offset) and everything works as expected, with no error\n printed, which means both functions return the same value.

  But when I run the algorithm with b(vertex,offset) instead of a(vertex,offset), a wrong answer comes out (although the algorithm doesn't break.

  Is there anything that I'm missing regarding macros? Don't they just replace text? I don't really understand this behavior.

  EDIT: Sorry I forgot to change the name of the fuction, b is now correct (it's the define function)

  EDIT2: Adding parentheses fixes the problem, so it should be:

  #define b(vertex, offset) (((vertex)*(numberOfoffsets)) + (offset))
  

  But other users suggested that I used inline functions instead, so now it's:

  static __inline__
  int b(int vertex, int offset) {
    return vertex*numberOfoffsets + offset;
  }
  
• How to always generate data for optional keys in a spec?

  If I have a spec like

  (clojure.spec/def ::person (clojure.spec/keys :req [::name ::address] :opt [::age]))
  

  And when I do

  (clojure.spec.gen/generate (clojure.spec/gen ::person))
  

  Is there any way to tell the generator to always consider the optional key(s) when generating data for it?

  I know that this could be done with custom generators but I wanted to know if there is a functionality already available for it or maybe a simpler approach which does not involve me defining a custom generator.
• How do you use "fdef" with maps in parameters?

  I'm trying to get fdef to successfully validate with a collection of maps as a parameter. I'm getting the following:

  (defn func
    [foo bar])
  (def t [{:a "hi ":b "jimbob"} {:a "hi" :b "johnboy"}])
  (spec/def ::a string?)
  (spec/def ::b string?)
  (spec/def ::c string?)
  (spec/def ::d string?)
  (spec/fdef func :args 
             (spec/cat :foo string? 
                       :bar (spec/+ (spec/keys 
                                      :req-un [::a ::b]
                                      :opt-un [::c ::d]))))
  (stest/instrument)
  (func "hello" t)
  
  => #'dmp-onboarding-service.handler/func
  => #'dmp-onboarding-service.handler/t
  => :dmp-onboarding-service.handler/a
  => :dmp-onboarding-service.handler/b
  => :dmp-onboarding-service.handler/c
  => :dmp-onboarding-service.handler/d
  => dmp-onboarding-service.handler/func
  => [dmp-onboarding-service.handler/send-email! dmp-onboarding-service.handler/func user/test]
  ExceptionInfo Call to #'dmp-onboarding-service.handler/func did not conform to spec:
  In: [1] val: [{:a "hi ", :b "jimbob"} {:a "hi", :b "johnboy"}] fails at: [:args :bar] predicate: map?
    clojure.core/ex-info (core.clj:4739)
  

  Clearly I'm missing how to couple args with their spec; this works:

  (spec/explain string? "hello")
  Success!
  => nil
  

  As does this

  (spec/explain (spec/+ (spec/keys
                          :req-un [::a ::b]
                          :opt-un [::c ::d]))
                        [{:a "hi ":b "jimbob"} {:a "hi" :b "johnboy"}])
  Success!
  => nil
  

  Any help is much appreciated!
• Compare between two specs values, Clojure.spec

  I have defined specs as -

  (s/def ::start integer?)
  (s/def ::end integer?)
  (s/def ::collection (s/keys :req-un [::start ::end]))
  

  It is working fine as (s/valid? ::collection {:start 9 :end 13})

  But now I also have to check that start should be less than end. How to do that? Is there a simpler way to do that without creating an another fn and check?
• Why is my Scalacheck test with a custom Generator failing after discarding many cases, and how do I fix this?

  I am a newbie with Scala and I am writing my first Scalacheck suite.

  I have a data structure in my program that essentially looks like a (List[Double], List[Double]) which is well-formed only if each element of _1 is strictly greater than the corresponding element of _2.

  Since it's slightly more complicated in practice (although for the purpose of this MWE we can pretend there's all there is to it), I've written a custom generator for it.

  I then added two trivial tests (including the most trivial of all, 1 == 1) and in both cases the tests fail, with the messageGave up after only XX passed tests. YYY tests were discarded.

  Why is it, and how do I fix it?

  Attached is my test suite and the output.

  ---

  package com.foo.bar
  
  import org.scalacheck._
  import Prop._
  import Arbitrary._
  
  object FooSpecification extends Properties("FooIntervals") {
  
    type FooIntervals = (List[Double], List[Double])
  
    /* This is supposed to be a tuple of lists s.t. each element of _1
     *  is < the corresponding element of _2
     * 
     *  e.g. (List(1,3,5), List(2,4,6))
     */
  
    implicit def arbInterval : Arbitrary[FooIntervals] =
      Arbitrary {
        /**
          * Yields a pair (low, high) s.t. low < high
          */
        def GenPair : Gen[(Double, Double)] = for {
          low <- arbitrary[Double]
          high <- arbitrary[Double].suchThat(_ > low)
        } yield (low, high)
  
        /**
          * Yields (List(x_1,...,x_n), List(y_1,...,y_n))
          * where x_i < y_i forall i and 1 <= n < 20
          */
        for {
          n <- Gen.choose(1,20)
          pairs : List[(Double, Double)] <- Gen.containerOfN[List, (Double, Double)](n, GenPair)
        } yield ((pairs.unzip._1, pairs.unzip._2))
      }
  
    property("1 == 1") = forAll {
      (b1: FooIntervals)
      =>
      1 == 1
    }
  
    property("_1.head < _2.head") = forAll {
      (b1: FooIntervals)
      =>
      b1._1.head < b1._2.head
    }
  }
  

  ---

  [info] ! FooIntervals.1 == 1: Gave up after only 32 passed tests. 501 tests were discarded.
  [info] ! FooIntervals._1.head < _2.head: Gave up after only 28 passed tests. 501 tests were discarded.
  [info] ScalaTest
  [info] Run completed in 1 second, 519 milliseconds.
  [info] Total number of tests run: 0
  [info] Suites: completed 0, aborted 0
  [info] Tests: succeeded 0, failed 0, canceled 0, ignored 0, pending 0
  [info] No tests were executed.
  [error] Failed: Total 1, Failed 1, Errors 0, Passed 0
  [error] Failed tests:
  [error]     com.foo.bar.FooSpecification
  
• What is generative testing in Clojure?

  I came across Generative Testing in Clojure with spec notion and would like to learn about it.

  Also providing some examples would be very useful.