Refactor fn/framework tests to use a common library.

kyaml/fn/framework/frameworktestutil/frameworktestutil.go

@@ -0,0 +1,172 @@
+// Copyright 2020 The Kubernetes Authors.
+// SPDX-License-Identifier: Apache-2.0
+
+// Package frameworktestutil contains utilities for testing functions written using the framework.
+package frameworktestutil
+
+import (
+	"bytes"
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"strings"
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+)
+
+// ResultsChecker tests a function by running it with predefined inputs and comparing
+// the outputs to expected results.
+type ResultsChecker struct {
+	// TestDataDirectory is the directory containing the testdata subdirectories.
+	// ResultsChecker will recurse into each test directory and run the Command
+	// if the directory contains both the ConfigInputFilename and at least one
+	// of ExpectedOutputFilname or ExpectedErrorFilename.
+	// Defaults to "testdata"
+	TestDataDirectory string
+
+	// ConfigInputFilename is the name of the config file provided as the first
+	// argument to the function.  Directories without this file will be skipped.
+	// Defaults to "config.yaml"
+	ConfigInputFilename string
+
+	// InputFilenameGlob matches function inputs
+	// Defaults to "input*.yaml"
+	InputFilenameGlob string
+
+	// ExpectedOutputFilname is the file with the expected output of the function
+	// Defaults to "expected.yaml".  Directories containing neither this file
+	// nore ExpectedErrorFilename will be skipped.
+	ExpectedOutputFilname string
+
+	// ExpectedErrorFilename is the file containing part of an expected error message
+	// Defaults to "error.yaml".  Directories containing neither this file
+	// nore ExpectedOutputFilname will be skipped.
+	ExpectedErrorFilename string
+
+	// Command provides the function to run.
+	Command func() cobra.Command
+}
+
+// Assert asserts the results for functions
+func (rc ResultsChecker) Assert(t *testing.T) bool {
+	if rc.TestDataDirectory == "" {
+		rc.TestDataDirectory = "testdata"
+	}
+	if rc.ConfigInputFilename == "" {
+		rc.ConfigInputFilename = "config.yaml"
+	}
+	if rc.ExpectedOutputFilname == "" {
+		rc.ExpectedOutputFilname = "expected.yaml"
+	}
+	if rc.ExpectedErrorFilename == "" {
+		rc.ExpectedErrorFilename = "error.yaml"
+	}
+	if rc.InputFilenameGlob == "" {
+		rc.InputFilenameGlob = "input*.yaml"
+	}
+
+	_ = filepath.Walk(rc.TestDataDirectory, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			t.FailNow()
+		}
+		if !info.IsDir() {
+			// skip non-directories
+			return nil
+		}
+		rc.compare(t, path)
+		return nil
+	})
+
+	return true
+}
+
+func (rc ResultsChecker) compare(t *testing.T, path string) {
+	// make sure this directory contains test data
+	configPath := filepath.Join(path, rc.ConfigInputFilename)
+	_, err := os.Stat(configPath)
+	if os.IsNotExist(err) {
+		// missing input
+		return
+	}
+	if !assert.NoError(t, err) {
+		t.FailNow()
+	}
+	args := []string{configPath}
+
+	if rc.InputFilenameGlob != "" {
+		inputs, err := filepath.Glob(filepath.Join(path, rc.InputFilenameGlob))
+		if !assert.NoError(t, err) {
+			t.FailNow()
+		}
+		args = append(args, inputs...)
+	}
+
+	var actualOutput, actualError bytes.Buffer
+	cmd := rc.Command()
+	cmd.SetArgs(args)
+	cmd.SetOut(&actualOutput)
+	cmd.SetErr(&actualError)
+
+	expectedOutput, expectedError := rc.getExpected(t, path)
+	if expectedError == "" && expectedOutput == "" {
+		// missing expected
+		return
+	}
+
+	err = cmd.Execute()
+
+	// Compae the results
+	if expectedError != "" && !assert.Error(t, err, actualOutput.String()) {
+		t.FailNow()
+	}
+	if expectedError == "" && !assert.NoError(t, err, actualError.String()) {
+		t.FailNow()
+	}
+	if !assert.Equal(t,
+		strings.TrimSpace(expectedOutput),
+		strings.TrimSpace(actualOutput.String()), actualError.String()) {
+		t.FailNow()
+	}
+	if !assert.Contains(t,
+		strings.TrimSpace(actualError.String()),
+		strings.TrimSpace(expectedError), actualOutput.String()) {
+		t.FailNow()
+	}
+}
+
+// getExpected reads the expected results and error files
+func (rc ResultsChecker) getExpected(t *testing.T, path string) (string, string) {
+	// read the expected results
+	var expectedOutput, expectedError string
+	if rc.ExpectedOutputFilname != "" {
+		_, err := os.Stat(filepath.Join(path, rc.ExpectedOutputFilname))
+		if !os.IsNotExist(err) && err != nil {
+			t.FailNow()
+		}
+		if err == nil {
+			// only read the file if it exists
+			b, err := ioutil.ReadFile(filepath.Join(path, rc.ExpectedOutputFilname))
+			if !assert.NoError(t, err) {
+				t.FailNow()
+			}
+			expectedOutput = string(b)
+		}
+	}
+	if rc.ExpectedErrorFilename != "" {
+		_, err := os.Stat(filepath.Join(path, rc.ExpectedErrorFilename))
+		if !os.IsNotExist(err) && err != nil {
+			t.FailNow()
+		}
+		if err == nil {
+			// only read the file if it exists
+			b, err := ioutil.ReadFile(filepath.Join(path, rc.ExpectedErrorFilename))
+			if !assert.NoError(t, err) {
+				t.FailNow()
+			}
+			expectedError = string(b)
+		}
+	}
+	return expectedOutput, expectedError
+}