Application core.

Author: otaviof

path_helper.go

@@ -0,0 +1,100 @@
+package main
+
+import (
+	"fmt"
+	"path"
+	"path/filepath"
+	"strings"
+)
+
+// PathHelper represents the application path-helper. Takes a configuration as input, and uses local
+// attributes to keep list of files and directories to compose PATH.
+type PathHelper struct {
+	config      *Config  // parsed command-line flags
+	files       []string // slice of files in path.d
+	directories []string // directories that will compose PATH
+}
+
+// logger for path-helper instance, skip printing when verbose is off.
+func (p *PathHelper) logger(format string, v ...interface{}) {
+	if p.config.Verbose {
+		fmt.Printf(fmt.Sprintf("# %s\n", format), v...)
+	}
+}
+
+// append a direcotry in global list, making sure it skips duplicates when setting is enabled.
+func (p *PathHelper) append(directory string) {
+	if p.config.SkipDuplicates {
+		for _, d := range p.directories {
+			if d == directory {
+				p.logger("[WARN] Skipping entry '%s', is already defined.", directory)
+				return
+			}
+		}
+	}
+	p.directories = append(p.directories, directory)
+}
+
+// globPathFiles load list of files in base directory. Returns errors when base directory does not
+// exist or when having issues to execute globing.
+func (p *PathHelper) globPathFiles() error {
+	baseDir := p.config.BaseDir
+	p.logger("Inspecting paths directory: '%s'", baseDir)
+	if !dirExists(baseDir) {
+		return fmt.Errorf("can't find base directory at '%s'", baseDir)
+	}
+
+	var err error
+	pattern := path.Join(baseDir, "*")
+	p.files, err = filepath.Glob(pattern)
+	return err
+}
+
+// gatherPathDirs based in path files, read and inspect direcotories listed in those. Can return
+// errors related to reading files.
+func (p *PathHelper) gatherPathDirs() error {
+	for _, file := range p.files {
+		p.logger("File '%s'", file)
+		directories, err := readLines(file)
+		if err != nil {
+			return fmt.Errorf("can't read file '%s': '%v'", file, err)
+		}
+
+		for _, directory := range directories {
+			p.logger("\t- '%s'", directory)
+			if p.config.SkipNotFound && !dirExists(directory) {
+				p.logger("[WARN] Directory '%s' (%s) is not found! Skipping.", directory, file)
+				continue
+			}
+			p.append(directory)
+		}
+	}
+	return nil
+}
+
+// pathDirsColonJoined return slice of direcotires joined by colon.
+func (p *PathHelper) pathDirsColonJoined() string {
+	return strings.Join(p.directories, ":")
+}
+
+// RenderExpression print out the shell expression exporting PATH. Will forward errors from methods
+// listing and reading path files, and inspecting direcotories present found in those files.
+func (p *PathHelper) RenderExpression() (string, error) {
+	if err := p.globPathFiles(); err != nil {
+		return "", err
+	}
+	if err := p.gatherPathDirs(); err != nil {
+		return "", err
+	}
+
+	return fmt.Sprintf("export PATH=\"%s\"", p.pathDirsColonJoined()), nil
+}
+
+// NewPathHelper instantiate a PathHelper type.
+func NewPathHelper(config *Config) *PathHelper {
+	return &PathHelper{
+		config:      config,
+		files:       []string{},
+		directories: []string{},
+	}
+}

path_helper_test.go

@@ -0,0 +1,79 @@
+package main
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestPathHelper(t *testing.T) {
+	config := &Config{Verbose: true, BaseDir: "./test/paths.d"}
+	expectedJoinedPaths := "/a/a/a:/b/b/b:/c/c/c:/d/d/d"
+
+	t.Run("without-duplicates", func(t *testing.T) {
+		t.Run("inspecting-directories-and-files", func(t *testing.T) {
+			inspectPathFilesAndDirectories(t, config, 1, expectedJoinedPaths)
+		})
+
+		t.Run("RenderExpression", func(t *testing.T) {
+			inspectRenderedExpression(t, config, expectedJoinedPaths)
+		})
+	})
+
+	t.Run("with-duplicates", func(t *testing.T) {
+		config.SkipDuplicates = true
+
+		t.Run("inspecting-directories-and-files", func(t *testing.T) {
+			inspectPathFilesAndDirectories(t, config, 1, expectedJoinedPaths)
+		})
+
+		t.Run("RenderExpression", func(t *testing.T) {
+			inspectRenderedExpression(t, config, expectedJoinedPaths)
+		})
+	})
+
+	t.Run("with-skip-not-found", func(t *testing.T) {
+		config.SkipDuplicates = true
+		config.SkipNotFound = true
+
+		t.Run("inspecting-directories-and-files", func(t *testing.T) {
+			inspectPathFilesAndDirectories(t, config, 0, "")
+		})
+
+		t.Run("RenderExpression", func(t *testing.T) {
+			inspectRenderedExpression(t, config, "")
+		})
+	})
+}
+
+func inspectPathFilesAndDirectories(
+	t *testing.T,
+	config *Config,
+	expectedLen int,
+	expectedJoinedPaths string,
+) {
+	p := NewPathHelper(config)
+	err := p.globPathFiles()
+	t.Logf("Error: '%#v", err)
+	assert.NoError(t, err)
+	t.Logf("Files: '%#v'", p.files)
+	assert.True(t, len(p.files) >= expectedLen)
+
+	err = p.gatherPathDirs()
+	t.Logf("Error: '%#v", err)
+	assert.NoError(t, err)
+	t.Logf("Directories: '%#v'", p.directories)
+	assert.True(t, len(p.directories) >= expectedLen)
+
+	assert.Equal(t, expectedJoinedPaths, p.pathDirsColonJoined())
+}
+
+func inspectRenderedExpression(t *testing.T, config *Config, expectedJoinedPaths string) {
+	p := NewPathHelper(config)
+	s, err := p.RenderExpression()
+	assert.NoError(t, err)
+	t.Logf("Expression: '%s'", s)
+	assert.NotEmpty(t, s)
+	assert.Equal(t, fmt.Sprintf("export PATH=\"%s\"", expectedJoinedPaths), s)
+}