R and Python loaders

Author: mbostock

src/dataloader.ts

@@ -6,6 +6,16 @@ import {maybeStat, prepareOutput} from "./files.js";
 
 const runningCommands = new Map<string, Promise<string>>();
 
+const languages = {
+  ".js": "node",
+  ".ts": "tsx",
+  ".py": "python3",
+  ".r": "RScript",
+  ".R": "RScript",
+  ".sh": "sh",
+  ".exe": null
+};
+
 export class Loader {
   /**
    * The command to run, such as "node" for a JavaScript loader, "tsx" for
@@ -52,13 +62,13 @@ export class Loader {
    * source root, if it exists. If there is no such loader, returns undefined.
    */
   static find(sourceRoot: string, targetPath: string): Loader | undefined {
-    for (const ext of [".js", ".ts", ".sh"]) {
+    for (const ext in languages) {
       const sourcePath = targetPath + ext;
       const path = join(sourceRoot, sourcePath);
       if (!existsSync(path)) continue;
       return new Loader({
-        command: ext === ".js" ? "node" : ext === ".ts" ? "tsx" : "sh",
-        args: [path],
+        command: languages[ext] ?? path,
+        args: languages[ext] == null ? [] : [path],
         path,
         sourceRoot,
         targetPath

test/dataloaders-test.ts

@@ -13,9 +13,24 @@ describe("data loaders are called with the appropriate command", () => {
     const out = await loader.load({verbose: false});
     assert.strictEqual(await readFile("test/" + out, "utf-8"), "tsx\n");
   });
-  it("a .sh data loader is called as a shell script", async () => {
+  it("a .sh data loader is called with sh", async () => {
     const loader = Loader.find("test", "dataloaders/data3.txt")!;
     const out = await loader.load({verbose: false});
     assert.strictEqual(await readFile("test/" + out, "utf-8"), "shell\n");
   });
+  it("a .exe data loader is invoked directly", async () => {
+    const loader = Loader.find("test", "dataloaders/data4.txt")!;
+    const out = await loader.load({verbose: false});
+    assert.strictEqual(await readFile("test/" + out, "utf-8"), "python3\n");
+  });
+  it("a .py data loader is called with python3", async () => {
+    const loader = Loader.find("test", "dataloaders/data5.txt")!;
+    const out = await loader.load({verbose: false});
+    assert.strictEqual(await readFile("test/" + out, "utf-8"), "python3\n");
+  });
+  it("a .R data loader is called with Rscript", async () => {
+    const loader = Loader.find("test", "dataloaders/data6.txt")!;
+    const out = await loader.load({verbose: false});
+    assert.strictEqual(await readFile("test/" + out, "utf-8"), "Rscript\n");
+  });
 });

test/dataloaders/data3.txt.sh

@@ -1,3 +1 @@
-#! /usr/bin/env bash
-
 echo "shell"

test/dataloaders/data4.txt.exe

@@ -0,0 +1,3 @@
+#!/usr/bin/env python3
+
+print("python3")

test/dataloaders/data5.txt.py

@@ -0,0 +1 @@
+print("python3")

test/dataloaders/data6.txt.R

@@ -0,0 +1 @@
+cat("Rscript\n")