I've got a switch case like this:
def someString = 'hello1234bla'
// ...
switch (someString) {
case {it.contains('1234')}:
doSomething()
break
case {it.contains('2468')}:
doSomethingElse()
break
default:
throw new Exception("ERROR: Number not found")
break
}
This seems to be quite a lot of code for something so seemingly simple. All I want is to have different functions be executed when someString contains a specific substring. Is there no simpler way to do this, apart from maybe an if-else cascade?
This is pretty close to what the comments above suggest, but I'll write out a working example with indentation etc and perhaps it will be a bit more readable:
def someString = "hello1234bla"
def found = [
'1234': { println "do something" },
'2468': { println "do something else" }
].find { pattern, action ->
if (someString.contains(pattern)) { action(); true }
else false
}
if (!found) throw new Exception("ERROR: Number not found")
this executes the first matching action and throws an exception if no matches were found. If you need to execute an action for every match, replace the find call with a findAll call.
Another way of executing code based on a pattern in the string is the groovy String eachMatch method:
def someString = "hello1234blae"
someString.eachMatch(/1234/) { println "do something" }
someString.eachMatch(/2468/) { println "do something else" }
which uses regular expressions and runs the closure (the block in the curlies after the eachMatch call) once for every match. Thus:
someString.eachMatch(/e/) { println "runs twice" }
on the above string would execute twice as there are two 'e' characters in the string.
Related
I have the Groovy code as below
def retVal = sh(returnStdout: true, script: "curl ${URI}; echo \$?")
println("Return value: ${retVal}") -> it printed 0
if (retVal == "0") {
println("Successfull") -> it doesn't go here
}
why the above condition can't be catched?
First of all, you seem to be using the Jenkins API incorrectly.
If all you need is the exit code of the process, use returnStatus: true:
def retVal = sh(returnStatus: true, script: "curl ${URI}")
if (retVal == 0) {
println 'success'
} else {
println "Something wrong, exit code was $retVal")
}
Now, if you really want the stdout instead, perhaps clean up the String first by calling trim() on it or try to match the String against a regex:
if (retValue ~== /\s*0\s*/) {
println "success"
} else {
println "Something wrong, exit code was '$retVal'")
}
I always put quotes around a value I print to make sure new-lines or whitespaces don't make me waste time with bad values.
Very basic question but I cannot find an answer:
I have the below code in a file g.groovy, and it functions in printing output:
#! /usr/env/groovy
def matchFiles = { match ->
new File(".").eachFile() {
if (it.name =~ match) {
println it
}
}
}
matchFiles('.groovy') prints ./g.groovy to screen.
But I want to capture the output of the closure in a variable and use it elsewhere, e.g.
def fileMatches = matchFiles('.groovy')
but cannot figure this out.
Tried changing println it to return it and then running
def fileMatches = matchFiles('.groovy')
fileMatches.println { it }
but this prints something like g$_run_closure2#4b168fa9
Any help is much appreciated, sorry for any incorrect nomenclature, very new to Groovy
according to the name matchFiles I assume you want to return all matched files
so, you have to define an array result variable where you are going to store each matched file
and then return this result variable after eachFile{...} closure
def matchFiles = { match ->
def result=[]
new File(".").eachFile {
if (it.name =~ match) {
result.add(it)
}
}
return result
}
println matchFiles(/.*/)
How can I check if multiple strings are empty in an elegant way? This is how I currently do it:
//if one required field is empty, close the connection
if (registerRequest.Email == "") ||
(registerRequest.PhoneNumber == "")||
(registerRequest.NachName =="") ||
(registerRequest.VorName =="") ||
(registerRequest.Password =="") ||
(registerRequest.VerificationId ==""){
//Could not proceed
w.WriteHeader(UNABLE_TO_PROCEED)
w.Write([]byte("Unable to register account."))
return
}
Note: You may use the solution below if you keep the "is-valid" condition in your handler, and also if you separate your condition into another function or method.
You can create a simple helper function, which has a variadic parameter, and you can call it with any number of string values:
func containsEmpty(ss ...string) bool {
for _, s := range ss {
if s == "" {
return true
}
}
return false
}
Example using it:
if containsEmpty("one", "two", "") {
fmt.Println("One is empty!")
} else {
fmt.Println("All is non-empty.")
}
if containsEmpty("one", "two", "three") {
fmt.Println("One is empty!")
} else {
fmt.Println("All is non-empty.")
}
Output of the above (try it on the Go Playground):
One is empty!
All is non-empty.
Your example would look like this:
if containsEmpty(registerRequest.Email,
registerRequest.PhoneNumber,
registerRequest.NachName,
registerRequest.VorName,
registerRequest.Password,
registerRequest.VerificationId) {
// One of the listed strings is empty
}
Also registerRequest is a kinda long name, it could be shortened to like r. If you can't or don't want to rename it in the surrounding code and if you want to shorten the condition, you could also do something like this:
If registerRequest is a pointer (or interface), you could also write:
if r := registerRequest; containsEmpty(r.Email,
r.PhoneNumber,
r.NachName,
r.VorName,
r.Password,
r.VerificationId) {
// One of the listed strings is empty
}
Actually you can do this even if registerRequest is not a pointer, but then the struct will be copied. If registerRequest is a struct, then you can take its address to avoid having to copy it like this:
if r := ®isterRequest; containsEmpty(r.Email,
r.PhoneNumber,
r.NachName,
r.VorName,
r.Password,
r.VerificationId) {
// One of the listed strings is empty
}
As Mario Santini mentioned in comment, a way to increase testability, encapsulate this logic, and decouple it from your handler method (which judging by the number of fields looks like it is at risk of changing at a different rate than your handler) could be to put this logic in a function:
func validRequest(registerRequest ?) bool {
return registerRequest.Email == "" ||
registerRequest.PhoneNumber == "" ||
registerRequest.NachName == "" ||
registerRequest.VorName == "" ||
registerRequest.Password == "" ||
registerRequest.VerificationId == ""
}
This now supports very focused, table driven tests, that can exercise what it means to be a valid request independent of any method involving writing headers.
It allows you to verify the valid/invalid path of your enclosing function, but to have very focused tests here. It also allows you to change what it means to be a valid request and verify it independent of your enclosing function.
You can use a switch:
switch "" {
case registerRequest.Email,
registerRequest.NachName,
registerRequest.Password,
registerRequest.PhoneNumber,
registerRequest.VerificationId,
registerRequest.VorName:
w.WriteHeader(UNABLE_TO_PROCEED)
w.Write([]byte("Unable to register account."))
return
}
https://golang.org/ref/spec#Switch_statements
How can I do this in Spock/groovy?
package org.jenkinsci.plugins
import hudson.matrix.*
import spock.lang.*
import org.junit.Rule
import org.jvnet.hudson.test.JenkinsRule
class xxxx extends Specification {
#Rule JenkinsRule rule = new JenkinsRule()
def 'matrix'() {
given:
def matrixProject = rule.createMatrixProject()
AxisList axl = new AxisList();
def axis = new TextAxis('TEST', "1", "2", "3")
axl.add(axis)
matrixProject.setAxes(axl)
expect: matrixProject.scheduleBuild2(0).get().logFile.text.contains("Some String!")
matrixProject.scheduleBuild2(0).get().getRuns().each(){
expect: it.logFile.text.contains("Another String")
}
}
}
specifically, how can I run a closure with a nested test? The "Another String" test doesn't work
Does this work?
def 'matrix'() {
given:
def matrixProject = rule.createMatrixProject()
def axis = new TextAxis('TEST', "1", "2", "3")
matrixProject.axes.add(axis)
expect:
with( matrixProject.scheduleBuild2(0).get() ) {
logFile.text.contains("Some String!")
runs.every { it.logFile.text.contains("Another String") }
}
}
}
Either use every instead of each, or use a nested assert.
I'm not sure if I understand your question well. However if by nested test you mean evaluating statement inside of each closure, why not just use assert
expect:
matrixProject.scheduleBuild2(0).get().logFile.text.contains("Some String!")
matrixProject.scheduleBuild2(0).get().getRuns().each() {
assert it.logFile.text.contains("Another String")
}
#tim_yates's approach also seems fine and it's more like Spock's way. I haven't tested it though.
EDIT
If you want be sure that all logFiles contain test string then use 'every' method as Peter suggested.
expect:
...
matrixProject.scheduleBuild2(0).get().getRuns().every {
it.text.contains('Another String')
}
Other approach, if you prefer to know how many logFiles don't contain test string on test fail count them and compare result size to zero:
expect:
...
matrixProject.scheduleBuild2(0).get().getRuns().count {
!it.text.contains('Another String')
} == 0
Yet another, if you like to know which files caused test to fail, get names of those which don't contain test string and compare that to an empty list:
expect:
...
matrixProject.scheduleBuild2(0).get().getRuns().findAll {
!it.text.contains('Another String')
}*.name == []
I would like to return from a closure, like one would if using a break statement in a loop.
For example:
largeListOfElements.each{ element->
if(element == specificElement){
// do some work
return // but this will only leave this iteration and start the next
}
}
In the above if statement I would like to stop iterating through the list and leave the closure to avoid unnecessary iterations.
I've seen a solution where an exception is thrown within the closure and caught outside, but I'm not too fond of that solution.
Are there any solutions to this, other than changing the code to avoid this kind of algorithm?
I think you want to use find instead of each (at least for the specified example). Closures don't directly support break.
Under the covers, groovy doesn't actually use a closure either for find, it uses a for loop.
Alternatively, you could write your own enhanced version of find/each iterator that takes a conditional test closure, and another closure to call if a match is found, having it break if a match is met.
Here's an example:
Object.metaClass.eachBreak = { ifClosure, workClosure ->
for (Iterator iter = delegate.iterator(); iter.hasNext();) {
def value = iter.next()
if (ifClosure.call(value)) {
workClosure.call(value)
break
}
}
}
def a = ["foo", "bar", "baz", "qux"]
a.eachBreak( { it.startsWith("b") } ) {
println "working on $it"
}
// prints "working on bar"
I think you're working on the wrong level of abstraction. The .each block does exactly what it says: it executes the closure once for each element. What you probably want instead is to use List.indexOf to find the right specificElement, and then do the work you need to do on it.
If you want to process all elements until a specific one was found you could also do something like this:
largeListOfElements.find { element ->
// do some work
element == specificElement
}
Although you can use this with any kind of "break condition".
I just used this to process the first n elements of a collection by returning
counter++ >= n
at the end of the closure.
As I understand groovy, the way to shortcut these kinds of loops would be to throw a user-defined exception. I don't know what the syntax would be (not a grrovy programmer), but groovy runs on the JVM so it would be something something like:
class ThisOne extends Exception {Object foo; ThisOne(Object foo) {this.foo=foo;}}
try { x.each{ if(it.isOk()) throw new ThisOne(it); false} }
catch(ThisOne x) { print x.foo + " is ok"; }
After paulmurray's answer I wasn't sure myself what would happen with an Exception thrown from within a closure, so I whipped up a JUnit Test Case that is easy to think about:
class TestCaseForThrowingExceptionFromInsideClosure {
#Test
void testEearlyReturnViaException() {
try {
[ 'a', 'b', 'c', 'd' ].each {
System.out.println(it)
if (it == 'c') {
throw new Exception("Found c")
}
}
}
catch (Exception exe) {
System.out.println(exe.message)
}
}
}
The output of the above is:
a
b
c
Found c
But remember that "one should NOT use Exceptions for flow control", see in particular this Stack Overflow question: Why not use exceptions as regular flow of control?
So the above solution is less than ideal in any case. Just use:
class TestCaseForThrowingExceptionFromInsideClosure {
#Test
void testEarlyReturnViaFind() {
def curSolution
[ 'a', 'b', 'c', 'd' ].find {
System.out.println(it)
curSolution = it
return (it == 'c') // if true is returned, find() stops
}
System.out.println("Found ${curSolution}")
}
}
The output of the above is also:
a
b
c
Found c
Today I faced a similar problem while working with each closure. I wanted to break the flow of execution based on my condition but couldn't do it.
The easiest way to do in groovy is to use any() on a list instead of each if you wish to return a boolean based on some condition.
Good ole for loop still works in Groovy for your use case
for (element in largeListOfElements) {
if(element == specificElement){
// do some work
return
}
}