Add VSCODE_OPTIONS and --vscode-option for Code flags

src/node/cli.ts

@@ -97,6 +97,7 @@ export interface UserProvidedArgs extends UserProvidedCodeArgs {
   "abs-proxy-base-path"?: string
   i18n?: string
   "idle-timeout-seconds"?: number
+  "vscode-option"?: string[]
   /* Positional arguments. */
   _?: string[]
 }
@@ -322,6 +323,13 @@ export const options: Options<Required<UserProvidedArgs>> = {
       "Override the reconnection grace time in seconds. Clients who disconnect for longer than this duration will need to \n" +
       "reload the window. Defaults to 10800 (3 hours).",
   },
+  "vscode-option": {
+    type: "string[]",
+    description:
+      "Pass an option straight through to the VS Code server as flag=value, or as a bare flag for a \n" +
+      "boolean. Repeatable; repeating the same flag builds an array. Use this to reach VS Code options \n" +
+      "code-server does not model itself, e.g. --vscode-option enable-sandbox --vscode-option agents=true.",
+  },
 }
 
 export const optionDescriptions = (opts: Partial<Options<Required<UserProvidedArgs>>> = options): string[] => {
@@ -643,6 +651,15 @@ export async function setDefaults(cliArgs: UserProvidedArgs, configArgs?: Config
     args["reconnection-grace-time"] = process.env.CODE_SERVER_RECONNECTION_GRACE_TIME
   }
 
+  // Space-separated, like NODE_OPTIONS.  Appended to any flags rather than
+  // replacing them so the two can be combined.
+  if (process.env.VSCODE_OPTIONS) {
+    args["vscode-option"] = [
+      ...(args["vscode-option"] ?? []),
+      ...process.env.VSCODE_OPTIONS.split(/\s+/).filter((option) => option),
+    ]
+  }
+
   if (process.env.CODE_SERVER_IDLE_TIMEOUT_SECONDS) {
     if (isNaN(Number(process.env.CODE_SERVER_IDLE_TIMEOUT_SECONDS))) {
       logger.info("CODE_SERVER_IDLE_TIMEOUT_SECONDS must be a number")
@@ -909,17 +926,58 @@ export interface CodeArgs extends UserProvidedCodeArgs {
   log?: string[]
 }
 
+/**
+ * Expand --vscode-option entries into VS Code server arguments.
+ *
+ * An entry is `flag=value`, or a bare `flag` meaning true.  A leading `--` on
+ * the flag is optional, so both spellings people reach for work.  Repeating a
+ * flag collects the values into an array, since several VS Code options take
+ * one.
+ *
+ * `true` and `false` become booleans rather than strings.  VS Code tests these
+ * flags for truthiness and the string "false" is truthy, so passing it along
+ * verbatim would quietly do the opposite of what was asked.
+ */
+export const parseVscodeOptions = (entries: string[]): Record<string, string | boolean | string[]> => {
+  const parsed: Record<string, string | boolean | string[]> = {}
+
+  for (const entry of entries) {
+    const [flag, rawValue] = splitOnFirstEquals(entry.replace(/^--/, ""))
+    if (!flag) {
+      throw new Error(`--vscode-option requires a flag name (got "${entry}")`)
+    }
+
+    const value: string | boolean =
+      typeof rawValue === "undefined" || rawValue === "true" ? true : rawValue === "false" ? false : rawValue
+
+    const existing = parsed[flag]
+    if (typeof existing === "undefined") {
+      parsed[flag] = value
+    } else if (Array.isArray(existing)) {
+      existing.push(String(value))
+    } else {
+      parsed[flag] = [String(existing), String(value)]
+    }
+  }
+
+  return parsed
+}
+
 /**
  * Convert our arguments to equivalent VS Code server arguments.
  * Does not add any extra arguments.
  */
 export const toCodeArgs = async (args: DefaultedArgs): Promise<CodeArgs> => {
+  // The passthrough option is ours; VS Code has no idea what it is.
+  const { "vscode-option": vscodeOptions, ...rest } = args
   return {
-    ...args,
+    ...rest,
     /** Type casting. */
     help: !!args.help,
     version: !!args.version,
     port: args.port?.toString(),
     log: args.log ? [args.log] : undefined,
-  }
+    // Last, so that reaching an option code-server does model still works.
+    ...parseVscodeOptions(vscodeOptions ?? []),
+  } as CodeArgs
 }

test/unit/node/cli.test.ts

@@ -51,6 +51,7 @@ describe("parser", () => {
     delete process.env.CODE_SERVER_RECONNECTION_GRACE_TIME
     delete process.env.VSCODE_PROXY_URI
     delete process.env.CS_DISABLE_PROXY
+    delete process.env.VSCODE_OPTIONS
     console.log = jest.fn()
   })
 
@@ -413,6 +414,17 @@ describe("parser", () => {
     })
   })
 
+  it("should use env var VSCODE_OPTIONS", async () => {
+    process.env.VSCODE_OPTIONS = "--enable-sandbox agents=true"
+    const args = parse(["--vscode-option", "verbose-logging"])
+
+    const defaultArgs = await setDefaults(args)
+    expect(defaultArgs).toEqual({
+      ...defaults,
+      "vscode-option": ["verbose-logging", "--enable-sandbox", "agents=true"],
+    })
+  })
+
   it("should use env var CS_DISABLE_GETTING_STARTED_OVERRIDE", async () => {
     process.env.CS_DISABLE_GETTING_STARTED_OVERRIDE = "1"
     const args = parse([])
@@ -1006,6 +1018,44 @@ describe("toCodeArgs", () => {
       _: [file],
     })
   })
+
+  it("should pass through --vscode-option", async () => {
+    const args = parse([
+      "--vscode-option",
+      "enable-sandbox",
+      "--vscode-option",
+      "agents=true",
+      "--vscode-option",
+      "enable-smoke-test-driver=false",
+    ])
+    expect(await toCodeArgs(await setDefaults(args))).toStrictEqual({
+      ...vscodeDefaults,
+      "enable-sandbox": true,
+      agents: true,
+      "enable-smoke-test-driver": false,
+    })
+  })
+
+  it("should collect a repeated --vscode-option into an array", async () => {
+    const args = parse([
+      "--vscode-option",
+      "locate-extension=a",
+      "--vscode-option",
+      "locate-extension=b",
+      "--vscode-option",
+      "locate-extension=c",
+    ])
+    expect(await toCodeArgs(await setDefaults(args))).toStrictEqual({
+      ...vscodeDefaults,
+      "locate-extension": ["a", "b", "c"],
+    })
+  })
+
+  it("should error if --vscode-option has no flag", async () => {
+    await expect(toCodeArgs(await setDefaults(parse(["--vscode-option", "=nothing"])))).rejects.toThrow(
+      "--vscode-option requires a flag name",
+    )
+  })
 })
 
 describe("optionDescriptions", () => {