4 files changed, 39 insertions, 0 deletions
diff --git a/js/process.ts b/js/process.ts
index 495f6a9ce..c47a5b5dd 100644
--- a/js/process.ts
+++ b/js/process.ts
@@ -27,6 +27,7 @@ export type ProcessStdio = "inherit" | "piped" | "null";
 export interface RunOptions {
   args: string[];
   cwd?: string;
+  env?: { [key: string]: string };
   stdout?: ProcessStdio;
   stderr?: ProcessStdio;
   stdin?: ProcessStdio;
@@ -107,11 +108,24 @@ export function run(opt: RunOptions): Process {
     opt.args.map(a => builder.createString(a))
   );
   const cwdOffset = opt.cwd == null ? -1 : builder.createString(opt.cwd);
+  const kvOffset: flatbuffers.Offset[] = [];
+  if (opt.env) {
+    for (const [key, val] of Object.entries(opt.env)) {
+      const keyOffset = builder.createString(key);
+      const valOffset = builder.createString(String(val));
+      msg.KeyValue.startKeyValue(builder);
+      msg.KeyValue.addKey(builder, keyOffset);
+      msg.KeyValue.addValue(builder, valOffset);
+      kvOffset.push(msg.KeyValue.endKeyValue(builder));
+    }
+  }
+  const envOffset = msg.Run.createEnvVector(builder, kvOffset);
   msg.Run.startRun(builder);
   msg.Run.addArgs(builder, argsOffset);
   if (opt.cwd != null) {
     msg.Run.addCwd(builder, cwdOffset);
   }
+  msg.Run.addEnv(builder, envOffset);
   if (opt.stdin) {
     msg.Run.addStdin(builder, stdioMap(opt.stdin!));
   }
diff --git a/js/process_test.ts b/js/process_test.ts
index e629dbe3d..9603fb1c8 100644
--- a/js/process_test.ts
+++ b/js/process_test.ts
@@ -186,3 +186,22 @@ testPerm({ run: true }, async function runOutput() {
   assertEqual(s, "hello");
   p.close();
 });
+
+testPerm({ run: true }, async function runEnv() {
+  const p = run({
+    args: [
+      "python",
+      "-c",
+      "import os, sys; sys.stdout.write(os.environ.get('FOO', '') + os.environ.get('BAR', ''))"
+    ],
+    env: {
+      FOO: "0123",
+      BAR: "4567"
+    },
+    stdout: "piped"
+  });
+  const output = await p.output();
+  const s = new TextDecoder().decode(output);
+  assertEqual(s, "01234567");
+  p.close();
+});
diff --git a/src/msg.fbs b/src/msg.fbs
index 7d8b89175..f3c47faf6 100644
--- a/src/msg.fbs
+++ b/src/msg.fbs
@@ -464,6 +464,7 @@ enum ProcessStdio: byte { Inherit, Piped, Null }
 table Run {
   args: [string];
   cwd: string;
+  env: [KeyValue];
   stdin: ProcessStdio;
   stdout: ProcessStdio;
   stderr: ProcessStdio;
diff --git a/src/ops.rs b/src/ops.rs
index a0646e923..a968ae6e1 100644
--- a/src/ops.rs
+++ b/src/ops.rs
@@ -1559,6 +1559,7 @@ fn op_run(
   assert_eq!(data.len(), 0);
   let inner = base.inner_as_run().unwrap();
   let args = inner.args().unwrap();
+  let env = inner.env().unwrap();
   let cwd = inner.cwd();
 
   let mut c = Command::new(args.get(0));
@@ -1567,6 +1568,10 @@ fn op_run(
     c.arg(arg);
   });
   cwd.map(|d| c.current_dir(d));
+  (0..env.len()).for_each(|i| {
+    let entry = env.get(i);
+    c.env(entry.key().unwrap(), entry.value().unwrap());
+  });
 
   c.stdin(subprocess_stdio_map(inner.stdin()));
   c.stdout(subprocess_stdio_map(inner.stdout()));