gomonop/cmd/matches/plugin.go

// The matches package contains the implementation of the `check_output_matches`
// plugin, which can be used to run an arbitrary command and check its output
// against various patterns. It can also be configured to do the same on an
// arbitrary file.
package matches // import nocternity.net/gomonop/cmd/matches

import (
	"regexp"

	"nocternity.net/gomonop/pkg/plugin"
	"nocternity.net/gomonop/pkg/results"
	"nocternity.net/gomonop/pkg/status"
)

// Program data for the string matches plugin.
type matchesPlugin struct {
	pluginFlags                     // Flags from the command line
	results        *results.Results // Plugin output state
	counters       []int            // Counters for each match
	unmatchedLines int              // Number of lines that didn't match anything
}

// Initialise the plugin.
func NewPlugin() plugin.Plugin {
	pluginInst := &matchesPlugin{
		results: results.New("String matches counter"),
	}
	pluginInst.parseArguments()
	return pluginInst
}

// Return the program's output value.
func (pluginInst *matchesPlugin) Results() *results.Results {
	return pluginInst.results
}

// Check the values that were specified from the command line. Returns true
// if the arguments made sense.
func (pluginInst *matchesPlugin) CheckArguments() bool {
	if pluginInst.dataSource == "" {
		pluginInst.results.SetState(status.StatusUnknown, "no data source specified")
		return false
	}

	if !pluginInst.strict && len(pluginInst.matches) == 0 {
		pluginInst.results.SetState(status.StatusUnknown, "would match anything")
		return false
	}

	for index := range pluginInst.matches {
		if pluginInst.matches[index].matchString == "" {
			pluginInst.results.SetState(status.StatusUnknown, "empty match string")
			pluginInst.results.AddLinef("(At match %d)", index+1)
			return false
		}
		if pluginInst.matches[index].isRegexp {
			rexp, err := regexp.Compile(pluginInst.matches[index].matchString)
			if err != nil {
				pluginInst.results.SetState(status.StatusUnknown, "Invalid regular expression")
				pluginInst.results.AddLine(err.Error())
				pluginInst.results.AddLinef("(At match %d)", index+1)
				return false
			}
			pluginInst.matches[index].compiledRe = rexp
		}
	}

	return true
}

// Run the check.
func (pluginInst *matchesPlugin) RunCheck() {
	pluginInst.counters = make([]int, len(pluginInst.matches))
	err := pluginInst.processData()
	pluginInst.checkResults(err)
}