Revert "Make if blocks work like a def-env (#4656)" (#4782)

This reverts commit 477f3be.

crates/nu-command/src/core_commands/if_.rs

@@ -37,88 +37,50 @@ impl Command for If {
  fn run(
  &self,
  engine_state: &EngineState,
- caller_stack: &mut Stack,
+ stack: &mut Stack,
  call: &Call,
  input: PipelineData,
  ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
  let cond = &call.positional[0];
- let then_block: CaptureBlock = call.req(engine_state, caller_stack, 1)?;
+ let then_block: CaptureBlock = call.req(engine_state, stack, 1)?;
  let else_case = call.positional.get(2);
 
- let result = eval_expression(engine_state, caller_stack, cond)?;
+ let result = eval_expression(engine_state, stack, cond)?;
  match &result {
  Value::Bool { val, .. } => {
  if *val {
  let block = engine_state.get_block(then_block.block_id);
- let mut callee_stack = caller_stack.captures_to_stack(&then_block.captures);
- let result = eval_block(
+ let mut stack = stack.captures_to_stack(&then_block.captures);
+ eval_block(
  engine_state,
- &mut callee_stack,
+ &mut stack,
  block,
  input,
  call.redirect_stdout,
  call.redirect_stderr,
- );
- let caller_env_vars = caller_stack.get_env_var_names(engine_state);
-
- // remove env vars that are present in the caller but not in the callee
- // (the callee hid them)
- for var in caller_env_vars.iter() {
- if !callee_stack.has_env_var(engine_state, var) {
- caller_stack.remove_env_var(engine_state, var);
- }
- }
-
- // add new env vars from callee to caller
- for env_vars in callee_stack.env_vars {
- for (var, value) in env_vars {
- caller_stack.add_env_var(var, value);
- }
- }
-
- result
+ )
  } else if let Some(else_case) = else_case {
  if let Some(else_expr) = else_case.as_keyword() {
  if let Some(block_id) = else_expr.as_block() {
- let result = eval_expression(engine_state, caller_stack, else_expr)?;
+ let result = eval_expression(engine_state, stack, else_expr)?;
  let else_block: CaptureBlock = FromValue::from_value(&result)?;
 
- let mut callee_stack =
- caller_stack.captures_to_stack(&else_block.captures);
+ let mut stack = stack.captures_to_stack(&else_block.captures);
  let block = engine_state.get_block(block_id);
- let result = eval_block(
+ eval_block(
  engine_state,
- &mut callee_stack,
+ &mut stack,
  block,
  input,
  call.redirect_stdout,
  call.redirect_stderr,
- );
-
- let caller_env_vars = caller_stack.get_env_var_names(engine_state);
-
- // remove env vars that are present in the caller but not in the callee
- // (the callee hid them)
- for var in caller_env_vars.iter() {
- if !callee_stack.has_env_var(engine_state, var) {
- caller_stack.remove_env_var(engine_state, var);
- }
- }
-
- // add new env vars from callee to caller
- for env_vars in callee_stack.env_vars {
- for (var, value) in env_vars {
- caller_stack.add_env_var(var, value);
- }
- }
-
- result
+ )
  } else {
- eval_expression(engine_state, caller_stack, else_expr)
+ eval_expression(engine_state, stack, else_expr)
  .map(|x| x.into_pipeline_data())
  }
  } else {
- eval_expression(engine_state, caller_stack, else_case)
+ eval_expression(engine_state, stack, else_case)
  .map(|x| x.into_pipeline_data())
  }
  } else {
@@ -150,11 +112,6 @@ impl Command for If {
  example: "if 5 < 3 { 'yes!' } else if 4 < 5 { 'no!' } else { 'okay!' }",
  result: Some(Value::test_string("no!")),
  },
- Example {
- description: "Update the environment based on a condition",
- example: r#"if true { let-env ENV_VAR = "new value" }"#,
- result: None,
- },
  ]
  }
 }

src/tests/test_engine.rs

@@ -350,16 +350,3 @@ fn default_value11() -> TestResult {
 fn default_value12() -> TestResult {
  fail_test(r#"def foo [--x:int = "a"] { $x }"#, "default value not int")
 }
-
-#[test]
-fn def_env_if() -> TestResult {
- run_test(r#"if true { let-env FOO = "QUX" }; $env.FOO"#, "QUX")
-}
-
-#[test]
-fn def_env_if2() -> TestResult {
- run_test(
- r#"if false { let-env FOO = "QUX" } else { let-env FOO = "QUUX" }; $env.FOO"#,
- "QUUX",
- )
-}