Despite my best efforts I've always found it hard to write clean taglib tests. Now thanks to Spock and GroovyShell things are getting easier...
void setup() {
mockDomain Invoice
}
def "Attachments icon has correct markup"() {
given:
Invoice invoice = new InvoiceBuilder().buildAndSave()
when:
renderAttachmentsIcon([target: invoice])
then:
valueOf('img.@id') == "toggle-attachments-${invoice.id}"
valueOf('script') == "\$('#toggle-attachments-${invoice.id}').bind('click', Books.attachments.toggle);"
}
Because I want to use GPath make assertions about the resulting HTML I've overriden TagLibSpec's methodMissing closure as follows...
def methodMissing(String name, args) {
String html = super.methodMissing(name, args)
createDocument(html)
}
void createDocument(String html) {
String xml = "<results>${html}</results>"
document = new XmlSlurper().parseText(xml)
}
And added helper methods for evaluating GPath expressions...
String valueOf(String gPath) {
evaluate(gPath).text()
}
GPathResult evaluate(String gPath) {
new GroovyShell(new Binding(document: document)).evaluate("document.${gPath}")
}
There's a little bit more to this story unfortunately...
Firstly my taglibs use the MarkupBuilder and when run from my Spock test this only outputs the opening tag of the first element I genererate. I haven't had a chance to look into this yet, but a workaround is to add "out << '' to the end of the taglib method
Secondly Spock interactions aren't yet as powerful as gmock, so I usually end up adding code to (g)mock grails taglibs.
Thirdly another one of my tests outputs in the HTML which causes the XML parsing to barf. The solution is to map the   entity to a known character (in this case underscore).
Finally there was a bug in Grails 1.3.3 / Spock 0.5 which breaks mockDomain. This is reportedly fixed in 1.3.4 and the latest Spock code, but I haven't tried upgrading yet.
Here's how things really look...
@WithGMock
class MetaAttachmentsTagLibSpec extends TagLibSpec {
def g
def document
void setup() {
g = mock()
mock(tagLib).getG().returns(g).stub()
mockDomain Invoice
PluginManagerHolder.pluginManager = [hasGrailsPlugin: { String name -> true }] as GrailsPluginManager // Workaround for JIRA GRAILS-6482
}
def cleanup() {
PluginManagerHolder.pluginManager = null // Workaround for JIRA GRAILS-6482
}
def "Attachments icon has correct markup"() {
given:
Invoice invoice = new InvoiceBuilder().buildAndSave()
g.resource(instanceOf(Map)).returns '/foo.jpg'
when:
renderAttachmentsIcon([target: invoice])
then:
valueOf('img.@id') == "toggle-attachments-${invoice.id}"
valueOf('img.@src') == "/foo.jpg"
valueOf('script') == "\$('#toggle-attachments-${invoice.id}').bind('click', Books.attachments.toggle);"
}
def methodMissing(String name, args) {
String html
play {
html = super.methodMissing(name, args)
}
createDocument(html)
}
def createDocument(String html) {
String xml = """<!DOCTYPE html [<!ENTITY nbsp "_">]>\n<results>${html}</results>"""
document = new XmlSlurper().parseText(xml)
}
}
And the method under test...
def renderAttachmentsIcon = { Map attrs, def body ->
String targetId = attrs.target.id
String iconId = "toggle-attachments-${targetId}"
String imgSrc = g.resource(dir:'/images/skin', file:'paperclip.png')
MarkupBuilder builder = new MarkupBuilder(out)
builder.img(id: iconId, src: imgSrc)
builder.script(type:'text/javascript') {
mkp.yield "\$('#${iconId}').bind('click', Books.attachments.toggle);"
}
out << '' // flush for unit tests
}
