fix(process): normalize capture environment overrides

src/process/capture/ProcessCaptureEnvironment.test.ts

@@ -0,0 +1,53 @@
+import { expect, it } from "vitest";
+
+import { processScenarioSchema } from "../../domain/process/processScenario.js";
+import { makeProcessCaptureEnvironment } from "./ProcessCaptureEnvironment.js";
+
+it("uses Windows environment identity for caller overrides and capture-owned values", () => {
+  const scenario = processScenarioSchema.parse({
+    executable: "node",
+    environment: {
+      path: "caller-bin",
+      term: "caller-terminal",
+      rea_process_run_id: "caller-token",
+    },
+  });
+  expect(
+    makeProcessCaptureEnvironment({
+      scenario,
+      hostEnvironment: {
+        Path: "host-bin",
+        TERM: "host-terminal",
+        REA_PROCESS_RUN_ID: "host-token",
+        OMITTED: undefined,
+      },
+      runId: "capture-token",
+      platform: "win32",
+    }),
+  ).toEqual({
+    PATH: "caller-bin",
+    TERM: "caller-terminal",
+    REA_PROCESS_RUN_ID: "capture-token",
+  });
+});
+
+it("preserves distinct POSIX names and supplies the terminal default", () => {
+  const scenario = processScenarioSchema.parse({
+    executable: "node",
+    environment: { path: "caller-bin", term: "lowercase-terminal" },
+  });
+  expect(
+    makeProcessCaptureEnvironment({
+      scenario,
+      hostEnvironment: { PATH: "host-bin", OMITTED: undefined },
+      runId: "capture-token",
+      platform: "linux",
+    }),
+  ).toEqual({
+    PATH: "host-bin",
+    path: "caller-bin",
+    term: "lowercase-terminal",
+    TERM: "xterm-256color",
+    REA_PROCESS_RUN_ID: "capture-token",
+  });
+});

src/process/capture/ProcessCaptureEnvironment.ts

@@ -1,24 +1,36 @@
 import type { ProcessScenario } from "../../domain/process/processScenario.js";
+import {
+  mergeEnvironmentOverrides,
+  snapshotEnvironment,
+} from "../snapshotEnvironment.js";
 
 interface ProcessCaptureEnvironmentOptions {
   readonly scenario: ProcessScenario;
   readonly runId: string;
   readonly hostEnvironment: Readonly<Record<string, string | undefined>>;
+  readonly platform?: NodeJS.Platform;
 }
 
 /** Build the child environment from the host plus caller-selected overrides. */
 export const makeProcessCaptureEnvironment = (
   options: ProcessCaptureEnvironmentOptions,
-): Record<string, string> => ({
-  ...Object.fromEntries(
-    Object.entries(options.hostEnvironment).filter(
-      (entry): entry is [string, string] => entry[1] !== undefined,
+): Record<string, string> => {
+  const platform = options.platform ?? process.platform;
+  const environment = snapshotEnvironment(
+    mergeEnvironmentOverrides(
+      options.hostEnvironment,
+      options.scenario.environment,
+      platform,
     ),
-  ),
-  ...options.scenario.environment,
-  TERM:
-    options.scenario.environment.TERM ??
-    options.hostEnvironment.TERM ??
-    "xterm-256color",
-  REA_PROCESS_RUN_ID: options.runId,
-});
+    platform,
+  );
+  return {
+    ...Object.fromEntries(
+      Object.entries(environment).filter(
+        (entry): entry is [string, string] => entry[1] !== undefined,
+      ),
+    ),
+    TERM: environment.TERM ?? "xterm-256color",
+    REA_PROCESS_RUN_ID: options.runId,
+  };
+};