Extract some functionality to its own packages

Like variable and template handling, and logging

internal/compiler/compiler.go

@@ -0,0 +1,12 @@
+package compiler
+
+import (
+	"github.com/go-task/task/internal/taskfile"
+)
+
+// Compiler handles compilation of a task before its execution.
+// E.g. variable merger, template processing, etc.
+type Compiler interface {
+	GetVariables(t *taskfile.Task, call taskfile.Call) (taskfile.Vars, error)
+	HandleDynamicVar(v taskfile.Var) (string, error)
+}

internal/compiler/env.go

@@ -0,0 +1,24 @@
+package compiler
+
+import (
+	"os"
+	"strings"
+
+	"github.com/go-task/task/internal/taskfile"
+)
+
+// GetEnviron the all return all environment variables encapsulated on a
+// taskfile.Vars
+func GetEnviron() taskfile.Vars {
+	var (
+		env = os.Environ()
+		m   = make(taskfile.Vars, len(env))
+	)
+
+	for _, e := range env {
+		keyVal := strings.SplitN(e, "=", 2)
+		key, val := keyVal[0], keyVal[1]
+		m[key] = taskfile.Var{Static: val}
+	}
+	return m
+}

internal/compiler/v1/compiler_v1.go

@@ -0,0 +1,145 @@
+package v1
+
+import (
+	"bytes"
+	"fmt"
+	"strings"
+	"sync"
+
+	"github.com/go-task/task/internal/compiler"
+	"github.com/go-task/task/internal/execext"
+	"github.com/go-task/task/internal/logger"
+	"github.com/go-task/task/internal/taskfile"
+	"github.com/go-task/task/internal/templater"
+)
+
+var _ compiler.Compiler = &CompilerV1{}
+
+type CompilerV1 struct {
+	Dir  string
+	Vars taskfile.Vars
+
+	Logger *logger.Logger
+
+	dynamicCache   map[string]string
+	muDynamicCache sync.Mutex
+}
+
+// GetVariables returns fully resolved variables following the priority order:
+// 1. Call variables (should already have been resolved)
+// 2. Environment (should not need to be resolved)
+// 3. Task variables, resolved with access to:
+//    - call, taskvars and environment variables
+// 4. Taskvars variables, resolved with access to:
+//    - environment variables
+func (c *CompilerV1) GetVariables(t *taskfile.Task, call taskfile.Call) (taskfile.Vars, error) {
+	merge := func(dest taskfile.Vars, srcs ...taskfile.Vars) {
+		for _, src := range srcs {
+			for k, v := range src {
+				dest[k] = v
+			}
+		}
+	}
+	varsKeys := func(srcs ...taskfile.Vars) []string {
+		m := make(map[string]struct{})
+		for _, src := range srcs {
+			for k := range src {
+				m[k] = struct{}{}
+			}
+		}
+		lst := make([]string, 0, len(m))
+		for k := range m {
+			lst = append(lst, k)
+		}
+		return lst
+	}
+	replaceVars := func(dest taskfile.Vars, keys []string) error {
+		r := templater.Templater{Vars: dest}
+		for _, k := range keys {
+			v := dest[k]
+			dest[k] = taskfile.Var{
+				Static: r.Replace(v.Static),
+				Sh:     r.Replace(v.Sh),
+			}
+		}
+		return r.Err()
+	}
+	resolveShell := func(dest taskfile.Vars, keys []string) error {
+		for _, k := range keys {
+			v := dest[k]
+			static, err := c.HandleDynamicVar(v)
+			if err != nil {
+				return err
+			}
+			dest[k] = taskfile.Var{Static: static}
+		}
+		return nil
+	}
+	update := func(dest taskfile.Vars, srcs ...taskfile.Vars) error {
+		merge(dest, srcs...)
+		// updatedKeys ensures template evaluation is run only once.
+		updatedKeys := varsKeys(srcs...)
+		if err := replaceVars(dest, updatedKeys); err != nil {
+			return err
+		}
+		return resolveShell(dest, updatedKeys)
+	}
+
+	// Resolve taskvars variables to "result" with environment override variables.
+	override := compiler.GetEnviron()
+	result := make(taskfile.Vars, len(c.Vars)+len(t.Vars)+len(override))
+	if err := update(result, c.Vars, override); err != nil {
+		return nil, err
+	}
+	// Resolve task variables to "result" with environment and call override variables.
+	merge(override, call.Vars)
+	if err := update(result, t.Vars, override); err != nil {
+		return nil, err
+	}
+	return result, nil
+}
+
+func (c *CompilerV1) HandleDynamicVar(v taskfile.Var) (string, error) {
+	if v.Static != "" || v.Sh == "" {
+		return v.Static, nil
+	}
+
+	c.muDynamicCache.Lock()
+	defer c.muDynamicCache.Unlock()
+
+	if c.dynamicCache == nil {
+		c.dynamicCache = make(map[string]string, 30)
+	}
+	if result, ok := c.dynamicCache[v.Sh]; ok {
+		return result, nil
+	}
+
+	var stdout bytes.Buffer
+	opts := &execext.RunCommandOptions{
+		Command: v.Sh,
+		Dir:     c.Dir,
+		Stdout:  &stdout,
+		Stderr:  c.Logger.Stderr,
+	}
+	if err := execext.RunCommand(opts); err != nil {
+		return "", &dynamicVarError{cause: err, cmd: opts.Command}
+	}
+
+	// Trim a single trailing newline from the result to make most command
+	// output easier to use in shell commands.
+	result := strings.TrimSuffix(stdout.String(), "\n")
+
+	c.dynamicCache[v.Sh] = result
+	c.Logger.VerboseErrf(`task: dynamic variable: '%s' result: '%s'`, v.Sh, result)
+
+	return result, nil
+}
+
+type dynamicVarError struct {
+	cause error
+	cmd   string
+}
+
+func (err *dynamicVarError) Error() string {
+	return fmt.Sprintf(`task: Command "%s" in taskvars file failed: %s`, err.cmd, err.cause)
+}

internal/logger/logger.go

@@ -0,0 +1,38 @@
+package logger
+
+import (
+	"fmt"
+	"io"
+)
+
+type Logger struct {
+	Stdout  io.Writer
+	Stderr  io.Writer
+	Verbose bool
+}
+
+func (l *Logger) Outf(s string, args ...interface{}) {
+	if len(args) == 0 {
+		s, args = "%s", []interface{}{s}
+	}
+	fmt.Fprintf(l.Stdout, s+"\n", args...)
+}
+
+func (l *Logger) VerboseOutf(s string, args ...interface{}) {
+	if l.Verbose {
+		l.Outf(s, args...)
+	}
+}
+
+func (l *Logger) Errf(s string, args ...interface{}) {
+	if len(args) == 0 {
+		s, args = "%s", []interface{}{s}
+	}
+	fmt.Fprintf(l.Stderr, s+"\n", args...)
+}
+
+func (l *Logger) VerboseErrf(s string, args ...interface{}) {
+	if l.Verbose {
+		l.Errf(s, args...)
+	}
+}

internal/templater/funcs.go

@@ -0,0 +1,52 @@
+package templater
+
+import (
+	"path/filepath"
+	"runtime"
+	"strings"
+	"text/template"
+
+	"github.com/Masterminds/sprig"
+)
+
+var (
+	templateFuncs template.FuncMap
+)
+
+func init() {
+	taskFuncs := template.FuncMap{
+		"OS":   func() string { return runtime.GOOS },
+		"ARCH": func() string { return runtime.GOARCH },
+		"catLines": func(s string) string {
+			s = strings.Replace(s, "\r\n", " ", -1)
+			return strings.Replace(s, "\n", " ", -1)
+		},
+		"splitLines": func(s string) []string {
+			s = strings.Replace(s, "\r\n", "\n", -1)
+			return strings.Split(s, "\n")
+		},
+		"fromSlash": func(path string) string {
+			return filepath.FromSlash(path)
+		},
+		"toSlash": func(path string) string {
+			return filepath.ToSlash(path)
+		},
+		"exeExt": func() string {
+			if runtime.GOOS == "windows" {
+				return ".exe"
+			}
+			return ""
+		},
+		// IsSH is deprecated.
+		"IsSH": func() bool { return true },
+	}
+	// Deprecated aliases for renamed functions.
+	taskFuncs["FromSlash"] = taskFuncs["fromSlash"]
+	taskFuncs["ToSlash"] = taskFuncs["toSlash"]
+	taskFuncs["ExeExt"] = taskFuncs["exeExt"]
+
+	templateFuncs = sprig.TxtFuncMap()
+	for k, v := range taskFuncs {
+		templateFuncs[k] = v
+	}
+}

internal/templater/templater.go

@@ -0,0 +1,73 @@
+package templater
+
+import (
+	"bytes"
+	"text/template"
+
+	"github.com/go-task/task/internal/taskfile"
+)
+
+// Templater is a help struct that allow us to call "replaceX" funcs multiple
+// times, without having to check for error each time. The first error that
+// happen will be assigned to r.err, and consecutive calls to funcs will just
+// return the zero value.
+type Templater struct {
+	Vars taskfile.Vars
+
+	strMap map[string]string
+	err    error
+}
+
+func (r *Templater) Replace(str string) string {
+	if r.err != nil || str == "" {
+		return ""
+	}
+
+	templ, err := template.New("").Funcs(templateFuncs).Parse(str)
+	if err != nil {
+		r.err = err
+		return ""
+	}
+
+	if r.strMap == nil {
+		r.strMap = r.Vars.ToStringMap()
+	}
+
+	var b bytes.Buffer
+	if err = templ.Execute(&b, r.strMap); err != nil {
+		r.err = err
+		return ""
+	}
+	return b.String()
+}
+
+func (r *Templater) ReplaceSlice(strs []string) []string {
+	if r.err != nil || len(strs) == 0 {
+		return nil
+	}
+
+	new := make([]string, len(strs))
+	for i, str := range strs {
+		new[i] = r.Replace(str)
+	}
+	return new
+}
+
+func (r *Templater) ReplaceVars(vars taskfile.Vars) taskfile.Vars {
+	if r.err != nil || len(vars) == 0 {
+		return nil
+	}
+
+	new := make(taskfile.Vars, len(vars))
+	for k, v := range vars {
+		new[k] = taskfile.Var{
+			Static: r.Replace(v.Static),
+			Sh:     r.Replace(v.Sh),
+		}
+	}
+	return new
+}
+
+func (r *Templater) Err() error {
+	return r.err
+}