Add execPath and resolvedExecPath

README.md

@@ -45,6 +45,14 @@ bunx jsr add @cross/utils
   - Generates a neatly formatted table representation of a 2D array and prints
     it to the console.
 
+- **execPath()**
+  - Get the pathto the current runtime executable.
+
+- **resolvedExecPath()**
+  - Get the path to the current runtime executable, as indicated by the PATH
+    variable. Could be a version independent link such as `...nvm/current...`
+    instead of `...nvm/<version>...`.
+
 **Classes**
 
 - **Colors**
@@ -135,3 +143,29 @@ functionality:
       ];
       table(myData);
       ```
+
+- **execPath(): Promise<string>**
+  - Returns the actual path to the current runtime executable.
+  - **Examples:**
+  ```javascript
+  const runtimeExecPath = await execPath();
+
+  // Log the runtime for debugging:
+  console.log(`Process started using ${runtimeExecPath}`);
+
+  // Spawn a child process with the same runtime:
+  const childProcess = spawn(runtimeExecPath, ["other-script.js"]);
+  ```
+
+- **resolvedExecPath(): Promise<string>**
+  - Returns the resolved path (through PATH) to the current runtime executable.
+  - **Examples:**
+  ```javascript
+  const runtimeExecPath = await resolvedExecPath();
+
+  // Log the runtime for debugging:
+  console.log(`Process started using ${runtimeExecPath}`);
+
+  // Spawn a child process with the same runtime:
+  const childProcess = spawn(runtimeExecPath, ["other-script.js"]);
+  ```

deno.json

@@ -1,16 +1,18 @@
 {
   "name": "@cross/utils",
-  "version": "0.8.2",
+  "version": "0.9.0",
   "exports": {
     ".": "./mod.ts",
     "./ansi": "./utils/ansi.ts",
     "./args": "./utils/args.ts",
     "./exit": "./utils/exit.ts",
     "./spawn": "./utils/spawn.ts",
     "./cwd": "./utils/cwd.ts",
-    "./table": "./utils/table.ts"
+    "./table": "./utils/table.ts",
+    "./execpath": "./utils/execpath.ts"
   },
   "imports": {
+    "@cross/fs": "jsr:@cross/fs@^0.0.7",
     "@cross/runtime": "jsr:@cross/runtime@^1.0.0",
     "@cross/test": "jsr:@cross/test@^0.0.9",
     "@std/assert": "jsr:@std/assert@^0.220.1"

mod.ts

@@ -3,3 +3,4 @@ export { args, ArgsParser } from "./utils/args.ts";
 export { Colors, Cursor, stripAnsi } from "./utils/ansi.ts";
 export { spawn } from "./utils/spawn.ts";
 export { cwd } from "./utils/cwd.ts";
+export { execPath, resolvedExecPath } from "./utils/execpath.ts";

utils/execpath.ts

@@ -0,0 +1,75 @@
+import { CurrentRuntime, Runtime } from "@cross/runtime";
+import { which } from "@cross/fs/stat";
+
+/**
+ * Cross-runtime compatible way to return the current executable path in a  manner, regardless of Node, Deno or Bun.
+ *
+ * @returns {string} The current working directory path.
+ * @throws
+ * @example
+ * // import { execPath } from "@cross/utils";
+ *
+ * const currentExecPath = execPath();
+ * console.log("The path to the current runtime executable is :", currentExecPath);
+ */
+export function execPath(): Promise<string> {
+  if (CurrentRuntime === Runtime.Deno) {
+    //@ts-ignore cross-runtime
+    return Deno.execPath();
+  } else if (
+    CurrentRuntime === Runtime.Node || CurrentRuntime === Runtime.Bun
+  ) {
+    //@ts-ignore cross-runtime
+    return process.execPath();
+  } else {
+    throw new Error(
+      `Cannot determine execPath using current runtime ('${CurrentRuntime}').`,
+    );
+  }
+}
+
+/**
+ * Cross-runtime compatible way to return the current executable path,
+ * prioritizing the executable's location within the user's PATH environment variable.
+ * This could result in a more generic path (e.g., `/home/.../nvm/current/node`) than the
+ * runtime's actual path (`/home/.../nvm/<version>/node`).
+ *
+ * @returns {string} The resolved executable path.
+ * @throws {Error} If the runtime executable cannot be found within the PATH.
+ * @example
+ * // import { resolvedExecPath } from "@cross/utils";
+ *
+ * const currentExecPath = await resolvedExecPath();
+ * console.log("The path to the current runtime executable is:", currentExecPath);
+ */
+export async function resolvedExecPath(): Promise<string> {
+  if (CurrentRuntime === Runtime.Deno) {
+    const foundDeno = await which("deno");
+    if (foundDeno !== null) {
+      return foundDeno;
+    } else {
+      //@ts-ignore cross-runtime
+      return Deno.execPath();
+    }
+  } else if (CurrentRuntime === Runtime.Node) {
+    const foundNode = await which("node");
+    if (foundNode !== null) {
+      return foundNode;
+    } else {
+      //@ts-ignore cross-runtime
+      return process.execPath();
+    }
+  } else if (CurrentRuntime === Runtime.Bun) {
+    const foundBun = await which("bun");
+    if (foundBun !== null) {
+      return foundBun;
+    } else {
+      //@ts-ignore cross-runtime
+      return process.execPath();
+    }
+  } else {
+    throw new Error(
+      `Cannot determine execPath using current runtime ('${CurrentRuntime}').`,
+    );
+  }
+}