feat: experiment taskfile envs take precedence over os envs

internal/env/env.go

@@ -4,22 +4,23 @@ import (
  "fmt"
  "os"
 
+ "github.com/go-task/task/v3/internal/experiments"
  "github.com/go-task/task/v3/taskfile/ast"
 )
 
 func Get(t *ast.Task) []string {
  if t.Env == nil {
  return nil
  }
-
  environ := os.Environ()
  for k, v := range t.Env.ToCacheMap() {
  if !isTypeAllowed(v) {
  continue
  }
-
- if _, alreadySet := os.LookupEnv(k); alreadySet {
- continue
+ if !experiments.EnvPrecedence.Enabled {
+ if _, alreadySet := os.LookupEnv(k); alreadySet {
+ continue
+ }
  }
  environ = append(environ, fmt.Sprintf("%s=%v", k, v))
  }

internal/experiments/experiments.go

@@ -29,6 +29,7 @@ var (
  RemoteTaskfiles Experiment
  AnyVariables Experiment
  MapVariables Experiment
+ EnvPrecedence Experiment
 )
 
 func init() {
@@ -37,6 +38,7 @@ func init() {
  RemoteTaskfiles = New("REMOTE_TASKFILES")
  AnyVariables = New("ANY_VARIABLES", "1", "2")
  MapVariables = New("MAP_VARIABLES", "1", "2")
+ EnvPrecedence = New("ENV_PRECEDENCE")
 }
 
 func New(xName string, enabledValues ...string) Experiment {
@@ -104,5 +106,6 @@ func List(l *logger.Logger) error {
  printExperiment(w, l, GentleForce)
  printExperiment(w, l, RemoteTaskfiles)
  printExperiment(w, l, MapVariables)
+ printExperiment(w, l, EnvPrecedence)
  return w.Flush()
 }

task_test.go

@@ -19,6 +19,7 @@ import (
 
  "github.com/go-task/task/v3"
  "github.com/go-task/task/v3/errors"
+ "github.com/go-task/task/v3/internal/experiments"
  "github.com/go-task/task/v3/internal/filepathext"
  "github.com/go-task/task/v3/taskfile/ast"
 )
@@ -60,7 +61,6 @@ func (fct fileContentTest) Run(t *testing.T) {
  for f := range fct.Files {
  _ = os.Remove(filepathext.SmartJoin(fct.Dir, f))
  }
-
  e := &task.Executor{
  Dir: fct.Dir,
  TempDir: task.TempDir{
@@ -71,9 +71,9 @@ func (fct fileContentTest) Run(t *testing.T) {
  Stdout: io.Discard,
  Stderr: io.Discard,
  }
+
  require.NoError(t, e.Setup(), "e.Setup()")
  require.NoError(t, e.Run(context.Background(), &ast.Call{Task: fct.Target}), "e.Run(target)")
-
  for name, expectContent := range fct.Files {
  t.Run(fct.name(name), func(t *testing.T) {
  path := filepathext.SmartJoin(e.Dir, name)
@@ -108,6 +108,7 @@ func TestEmptyTaskfile(t *testing.T) {
 }
 
 func TestEnv(t *testing.T) {
+ t.Setenv("QUX", "from_os")
  tt := fileContentTest{
  Dir: "testdata/env",
  Target: "default",
@@ -116,9 +117,21 @@ func TestEnv(t *testing.T) {
  "local.txt": "GOOS='linux' GOARCH='amd64' CGO_ENABLED='0'\n",
  "global.txt": "FOO='foo' BAR='overriden' BAZ='baz'\n",
  "multiple_type.txt": "FOO='1' BAR='true' BAZ='1.1'\n",
+ "not-overriden.txt": "QUX='from_os'\n",
  },
  }
  tt.Run(t)
+ t.Setenv("TASK_X_ENV_PRECEDENCE", "1")
+ experiments.EnvPrecedence = experiments.New("ENV_PRECEDENCE")
+ ttt := fileContentTest{
+ Dir: "testdata/env",
+ Target: "overriden",
+ TrimSpace: false,
+ Files: map[string]string{
+ "overriden.txt": "QUX='from_taskfile'\n",
+ },
+ }
+ ttt.Run(t)
 }
 
 func TestVars(t *testing.T) {

testdata/env/Taskfile.yml

@@ -8,12 +8,14 @@ env:
  FOO: foo
  BAR: bar
  BAZ: "{{.BAZ}}"
+ QUX: from_taskfile
 
 tasks:
  default:
  cmds:
  - task: local
  - task: global
+ - task: not-overriden
  - task: multiple_type
 
  local:
@@ -40,3 +42,11 @@ tasks:
  BAZ: 1.1
  cmds:
  - echo "FOO='$FOO' BAR='$BAR' BAZ='$BAZ'" > multiple_type.txt
+
+ not-overriden:
+ cmds:
+ - echo "QUX='$QUX'" > not-overriden.txt
+
+ overriden:
+ cmds:
+ - echo "QUX='$QUX'" > overriden.txt

website/docs/experiments/env_precedence.mdx

@@ -0,0 +1,70 @@
+---
+draft: false # Hide in production
+slug: '/experiments/env-precedence'
+---
+
+# Env Precedence (#1038)
+
+:::caution
+
+All experimental features are subject to breaking changes and/or removal _at any
+time_. We strongly recommend that you do not use these features in a production
+environment. They are intended for testing and feedback only.
+
+:::
+
+:::warning
+
+This experiment breaks the following functionality:
+
+- environment variable will take precedence over OS environment variables
+
+:::
+
+:::info
+
+To enable this experiment, set the environment variable: `TASK_X_ENV_PRECEDENCE=1`.
+Check out [our guide to enabling experiments ][enabling-experiments] for more
+information.
+
+:::
+
+Before this experiment, the OS variable took precedence over the task environment variable. This experiment changes the precedence to make the task environment variable take precedence over the OS variable.
+
+Consider the following example:
+
+```yml
+version: '3'
+
+tasks:
+ default:
+ env:
+ KEY: 'other'
+ cmds:
+ - echo "$KEY"
+```
+Running `KEY=some task` before this experiment, the output would be `some`, but after this experiment, the output would be `other`.
+
+If you still want to get the OS variable, you can use the template function env like follow : `{{env "OS_VAR"}}`.
+
+```yml
+version: '3'
+
+tasks:
+ default:
+ env:
+ KEY: 'other'
+ cmds:
+ - echo "$KEY"
+ - echo {{env "KEY"}}
+```
+Running `KEY=some task`, the output would be `other` and `some`.
+
+Like other variables/envs, you can also fall back to a given value using the default template function:
+```yml
+MY_ENV: '{{.MY_ENV | default "fallback"}}'
+```
+
+{/* prettier-ignore-start */}
+[enabling-experiments]: ./experiments.mdx#enabling-experiments
+{/* prettier-ignore-end */}