chore: stop ignoring src/config/env

src/config/env/using_flags.rs

@@ -0,0 +1,70 @@
+//! Using/namespace-related environment flags
+//!
+//! This module groups all `using` system and namespace flags.
+//! Use this for IDE autocomplete to discover using/namespace flags easily.
+
+use super::warn_alias_once;
+
+pub fn enable_using() -> bool {
+    // Phase 15: デフォルトON（using systemはメイン機能）
+    // NYASH_ENABLE_USING=0 で明示的に無効化可能。HAKO_ENABLE_USING は互換のため受理（警告）。
+    match std::env::var("NYASH_ENABLE_USING").ok().as_deref() {
+        Some("0") | Some("false") | Some("off") => return false,
+        Some(_) => return true,
+        None => {}
+    }
+    // Fallback to alias
+    if let Some(v) = std::env::var("HAKO_ENABLE_USING").ok() {
+        warn_alias_once("HAKO_ENABLE_USING", "NYASH_ENABLE_USING");
+        let lv = v.to_ascii_lowercase();
+        return !(lv == "0" || lv == "false" || lv == "off");
+    }
+    true // default ON
+}
+
+// ---- Using profiles (dev|ci|prod) ----
+/// Return using profile string; default is "dev".
+pub fn using_profile() -> String {
+    std::env::var("NYASH_USING_PROFILE").unwrap_or_else(|_| "dev".to_string())
+}
+
+/// True when using profile is prod (disables some dev-only behaviors).
+pub fn using_is_prod() -> bool {
+    using_profile().eq_ignore_ascii_case("prod")
+}
+
+/// True when using profile is ci.
+pub fn using_is_ci() -> bool {
+    using_profile().eq_ignore_ascii_case("ci")
+}
+
+/// True when using profile is dev (default).
+pub fn using_is_dev() -> bool {
+    using_profile().eq_ignore_ascii_case("dev")
+}
+
+/// Allow `using "path"` statements in source (dev-only by default).
+pub fn allow_using_file() -> bool {
+    // SSOT 徹底: 全プロファイルで既定禁止（nyash.toml を唯一の真実に）
+    // 明示オーバーライドでのみ許可（開発用緊急時）
+    match std::env::var("NYASH_ALLOW_USING_FILE").ok().as_deref() {
+        Some("1") | Some("true") | Some("on") => true,
+        _ => false,
+    }
+}
+
+/// Determine whether AST prelude merge for `using` is enabled.
+/// Precedence:
+/// 1) Explicit env `NYASH_USING_AST` = 1/true/on → enabled, = 0/false/off → disabled
+/// 2) Default by profile: dev/ci → ON, prod → OFF
+pub fn using_ast_enabled() -> bool {
+    match std::env::var("NYASH_USING_AST")
+        .ok()
+        .as_deref()
+        .map(|v| v.to_ascii_lowercase())
+    {
+        Some(ref s) if s == "1" || s == "true" || s == "on" => true,
+        Some(ref s) if s == "0" || s == "false" || s == "off" => false,
+        _ => !using_is_prod(), // dev/ci → true, prod → false
+    }
+}