参考所有分组：完善OPFS参数备份桥接

结论：按 LinuxCNC rs274ngc_pre.cc save_parameters()/restore_parameters() 语义，补齐浏览器 OPFS 参数文件 .bak 持久化；未扩展 smoke 解析行为。

验证：./test-native.sh；./test-linuxcnc-source-link.sh；./test-web-wasm-node-smoke.sh；./test-web-wasm-browser-smoke.sh。

web/src/wasm-core.js

@@ -703,10 +703,19 @@ export async function createWasmSimulator(moduleOptions = {}) {
         throw new Error("OPFS workspace is not available for parameter file persistence");
       }
       cleanupLinuxCncParameterFiles(module);
-      await opfs.loadParameterFile(parameterPath);
+      const previousParameterFile = await opfs.loadParameterFile(parameterPath);
       try {
         const events = parseText(program, dialect, options, { keepLinuxCncParameterFiles: true });
         await opfs.persistParameterFile(parameterPath);
+        // LinuxCNC source basis: rs274ngc_pre.cc save_parameters()
+        // links the previous parameter file to filename + ".bak" before
+        // replacing filename. Browser filesystems may not expose that link
+        // through the WASM mirror, so preserve the loaded OPFS file here.
+        if (previousParameterFile === null) {
+          await opfs.removeFile(`${parameterPath}.bak`);
+        } else if (!(await opfs.exists(`${parameterPath}.bak`))) {
+          await opfs.writeFile(`${parameterPath}.bak`, previousParameterFile);
+        }
         return events;
       } finally {
         cleanupLinuxCncParameterFiles(module);

web/test-browser-wasm-smoke-app-sections.js

@@ -28,6 +28,20 @@ export async function runBrowserAppOpfsSections(context) {
       const savedParameterFile = new TextDecoder().decode(await appSimulator.fs.opfs.readFile("parameters/rs274ngc.var"));
       expectIncludes(savedParameterFile, "5161\t1.000000",
         "app frame did not persist LinuxCNC parameter state into OPFS");
+      await appSimulator.fs.opfs.removeFile("parameters/rs274ngc.var.bak");
+      parseAppFrameProgram(appFrame, "G21 G90\nG0 X2\nG28.1\nM30\n");
+      await waitFor(
+        () => appFrame.contentDocument?.querySelector("#axisX")?.value === "2.000",
+        "app frame did not parse second program for parameter backup coverage",
+      );
+      // LinuxCNC source basis: rs274ngc_pre.cc save_parameters()
+      // preserves the previous parameter file as filename + ".bak".
+      const updatedParameterFile = new TextDecoder().decode(await appSimulator.fs.opfs.readFile("parameters/rs274ngc.var"));
+      expectIncludes(updatedParameterFile, "5161\t2.000000",
+        "app frame did not replace LinuxCNC parameter state after second parse");
+      const savedParameterBackup = new TextDecoder().decode(await appSimulator.fs.opfs.readFile("parameters/rs274ngc.var.bak"));
+      expectIncludes(savedParameterBackup, "5161\t1.000000",
+        "app frame did not persist LinuxCNC parameter backup into OPFS");
     } finally {
       await disposeAppFrame(appFrame);
     }
@@ -38,7 +52,7 @@ export async function runBrowserAppOpfsSections(context) {
       await waitForAppControls(restoredAppFrame, "restored app frame did not load CNC controls");
       await waitFor(() => {
         const restoredInput = restoredAppFrame.contentDocument?.querySelector("#programInput");
-        return restoredInput?.value === "G21 G90\nG0 X1\nG28.1\nM30\n";
+        return restoredInput?.value === "G21 G90\nG0 X2\nG28.1\nM30\n";
       }, "app frame did not restore current program from OPFS after reload");
       await waitForAppAlarm(
         restoredAppFrame,
@@ -48,7 +62,7 @@ export async function runBrowserAppOpfsSections(context) {
       await getAppFrameSimulator(restoredAppFrame, "restored app frame did not create OPFS simulator workspace");
       parseAppFrameProgram(
         restoredAppFrame,
-        "G21 G90\nF100\nO10 if [#5161 EQ 1]\nG1 X12\nO10 endif\nM30\n",
+        "G21 G90\nF100\nO10 if [#5161 EQ 2]\nG1 X12\nO10 endif\nM30\n",
       );
       await waitForAppAlarm(
         restoredAppFrame,

web/test-browser-wasm-smoke-opfs-parameter-sections.js

@@ -9,6 +9,7 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
     expectText,
     expectWasmFilesMissing,
     near,
+    readOpfsText,
     removeWasmPathIfExists,
     runSection,
     withSmokeSimulator,
@@ -21,9 +22,7 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
       "linuxcnc",
       { backend: "linuxcnc-rs274" },
     );
-    const opfsParameterFile = new TextDecoder().decode(
-      await simulator.fs.opfs.readFile("parameters/rs274ngc.var"),
-    );
+    const opfsParameterFile = await readOpfsText(simulator, "parameters/rs274ngc.var");
     expectIncludes(opfsParameterFile, "5161\t1.000000", "LinuxCNC parameter file was not persisted into OPFS");
   });
 
@@ -42,6 +41,20 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
     });
   });
 
+  await runSection("opfs default parameter backup", async () => {
+    // LinuxCNC source basis: rs274ngc_pre.cc save_parameters()
+    // preserves the previous default parameter file as filename + ".bak".
+    await simulator.parseWithParameterFile(
+      "G21 G90\nM30\n",
+      "parameters/rs274ngc.var",
+      "linuxcnc",
+      { backend: "linuxcnc-rs274" },
+    );
+    const defaultParameterBackup = await readOpfsText(simulator, "parameters/rs274ngc.var.bak");
+    expectIncludes(defaultParameterBackup, "5161\t1.000000",
+      "LinuxCNC default OPFS parameter backup did not preserve the previous file");
+  });
+
   await runSection("opfs parameter temporary cleanup", async () => {
     await simulator.fs.opfs.writeFile("parameters/rs274ngc.var.new", "stale temporary parameter file\n");
     // LinuxCNC source basis: rs274ngc_pre.cc save_parameters() writes
@@ -73,24 +86,49 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
     simulator.fs.module.FS.writeFile("rs274ngc.var", "5161\t2.000000\n");
     simulator.fs.module.FS.writeFile("rs274ngc.var.bak", "5161\t1.000000\n");
     await simulator.fs.opfs.persistParameterFile("parameters/backup-bridge.var");
-    const opfsParameterBackup = new TextDecoder().decode(
-      await simulator.fs.opfs.readFile("parameters/backup-bridge.var.bak"),
-    );
+    const opfsParameterBackup = await readOpfsText(simulator, "parameters/backup-bridge.var.bak");
     expectIncludes(opfsParameterBackup, "5161\t1.000000",
       "LinuxCNC parameter backup file was not bridged into OPFS");
   });
 
+  await runSection("opfs parameter backup after existing save", async () => {
+    await simulator.fs.opfs.writeFile("parameters/existing-save.var", "5161\t3.000000\n");
+    // LinuxCNC source basis: rs274ngc_pre.cc save_parameters()
+    // unlinks filename + ".bak", links the current parameter file to
+    // filename + ".bak", then renames filename + ".new" over filename.
+    await simulator.parseWithParameterFile(
+      "G21 G90\nG0 X4\nG28.1\nM30\n",
+      "parameters/existing-save.var",
+      "linuxcnc",
+      { backend: "linuxcnc-rs274" },
+    );
+    const existingSaveParameterFile = await readOpfsText(simulator, "parameters/existing-save.var");
+    expectIncludes(existingSaveParameterFile, "5161\t4.000000",
+      "LinuxCNC existing OPFS parameter file was not replaced after save");
+    const existingSaveParameterBackup = await readOpfsText(simulator, "parameters/existing-save.var.bak");
+    expectIncludes(existingSaveParameterBackup, "5161\t3.000000",
+      "LinuxCNC existing OPFS parameter backup did not preserve the previous file");
+    await expectMissingOpfsFile(
+      () => simulator.fs.opfs.readFile("parameters/existing-save.var.new"),
+      "LinuxCNC existing OPFS parameter temporary file remained after save",
+    );
+  });
+
   await runSection("opfs parameter stale backup cleanup", async () => {
+    await simulator.fs.opfs.removeFile("parameters/stale-backup-cleanup.var");
+    await simulator.fs.opfs.removeFile("parameters/stale-backup-cleanup.var.new");
+    await simulator.fs.opfs.removeFile("parameters/stale-backup-cleanup.var.bak");
+    await simulator.fs.opfs.writeFile("parameters/stale-backup-cleanup.var.bak", "stale backup without main file\n");
     removeWasmPathIfExists(simulator, "rs274ngc.var.bak");
     removeWasmPathIfExists(simulator, "/rs274ngc.var.bak");
     await simulator.parseWithParameterFile(
       "G21 G90\nM30\n",
-      "parameters/rs274ngc.var",
+      "parameters/stale-backup-cleanup.var",
       "linuxcnc",
       { backend: "linuxcnc-rs274" },
     );
     await expectMissingOpfsFile(
-      () => simulator.fs.opfs.readFile("parameters/rs274ngc.var.bak"),
+      () => simulator.fs.opfs.readFile("parameters/stale-backup-cleanup.var.bak"),
       "stale LinuxCNC parameter backup file remained in OPFS",
     );
     // LinuxCNC source basis: rs274ngc_pre.cc save_parameters()
@@ -111,6 +149,9 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
   });
 
   await runSection("opfs missing parameter file creation", async () => {
+    await simulator.fs.opfs.removeFile("parameters/missing-main.var");
+    await simulator.fs.opfs.removeFile("parameters/missing-main.var.new");
+    await simulator.fs.opfs.removeFile("parameters/missing-main.var.bak");
     await simulator.fs.opfs.writeFile("parameters/missing-main.var.bak", "stale backup without main file\n");
     await simulator.fs.opfs.writeFile("parameters/missing-main.var.new", "stale temporary without main file\n");
     // LinuxCNC source basis: rs274ngc_pre.cc save_parameters() unlinks
@@ -124,13 +165,15 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
       "linuxcnc",
       { backend: "linuxcnc-rs274" },
     );
-    const missingMainParameterFile = new TextDecoder().decode(
-      await simulator.fs.opfs.readFile("parameters/missing-main.var"),
-    );
+    const missingMainParameterFile = await readOpfsText(simulator, "parameters/missing-main.var");
     expectIncludes(missingMainParameterFile, "5220\t1.000000",
       "LinuxCNC missing parameter file was not created through OPFS");
     expectIncludes(missingMainParameterFile, "5161\t0.000000",
       "LinuxCNC missing parameter file did not include required G28 parameter");
+    await expectMissingOpfsFile(
+      () => simulator.fs.opfs.readFile("parameters/missing-main.var.bak"),
+      "stale LinuxCNC missing-parameter backup remained in OPFS after first creation",
+    );
     const missingMainRestoreEvents = await simulator.parseWithParameterFile(
       "G21 G90\nF100\nO10 if [#5220 EQ 1]\nG1 X6\nO10 endif\n",
       "parameters/missing-main.var",
@@ -139,10 +182,9 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
     );
     expectEvent(missingMainRestoreEvents, (event) => event.type === "linear-feed" && near(event.end.x, 6),
       "LinuxCNC-created missing OPFS parameter file was not restored on the next parse");
-    await expectMissingOpfsFile(
-      () => simulator.fs.opfs.readFile("parameters/missing-main.var.bak"),
-      "stale LinuxCNC missing-parameter backup remained in OPFS",
-    );
+    const missingMainParameterBackup = await readOpfsText(simulator, "parameters/missing-main.var.bak");
+    expectIncludes(missingMainParameterBackup, "5220\t1.000000",
+      "LinuxCNC-created OPFS parameter file was not backed up on the next successful save");
     expectMissingWasmPath(
       () => simulator.fs.module.FS.readFile("rs274ngc.var.bak"),
       "stale LinuxCNC missing-parameter backup remained in WASM FS",
@@ -169,9 +211,7 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
       "Parameter file out of order",
       "LinuxCNC accepted an out-of-order OPFS parameter file",
     );
-    const outOfOrderParameterFile = new TextDecoder().decode(
-      await simulator.fs.opfs.readFile("parameters/out-of-order.var"),
-    );
+    const outOfOrderParameterFile = await readOpfsText(simulator, "parameters/out-of-order.var");
     expectText(outOfOrderParameterFile, "5162\t1.000000\n5161\t1.000000\n",
       "LinuxCNC persisted an out-of-order OPFS parameter file after restore failure");
     expectMissingWasmPath(
@@ -189,9 +229,7 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
       "Parameter number out of range",
       "LinuxCNC accepted an out-of-range OPFS parameter file",
     );
-    const outOfRangeParameterFile = new TextDecoder().decode(
-      await simulator.fs.opfs.readFile("parameters/out-of-range.var"),
-    );
+    const outOfRangeParameterFile = await readOpfsText(simulator, "parameters/out-of-range.var");
     expectText(outOfRangeParameterFile, "0\t1.000000\n",
       "LinuxCNC persisted an out-of-range OPFS parameter file after restore failure");
     expectMissingWasmPath(
@@ -209,9 +247,7 @@ export async function runBrowserOpfsParameterSections(context, simulator) {
       "",
       "LinuxCNC accepted a failing parse that should not persist parameters",
     );
-    const failedParseParameterFile = new TextDecoder().decode(
-      await simulator.fs.opfs.readFile("parameters/failed-parse.var"),
-    );
+    const failedParseParameterFile = await readOpfsText(simulator, "parameters/failed-parse.var");
     if (failedParseParameterFile.includes("5161\t1.000000")) {
       throw new Error("LinuxCNC persisted failed parse parameter updates into OPFS");
     }