chore: add arg-parser and put the config under test

This commit is biggish because it adds a big chunk of tests
that weren't there before. While it would be arguably that
testing every flag might be too much, because I'm changing
how arguments are parsed, I want to have this as a safeline.

Author: kmruiz

package-lock.json

@@ -75,6 +75,7 @@
     "@mongodb-js/device-id": "^0.3.1",
     "@mongodb-js/devtools-connect": "^3.9.2",
     "@mongodb-js/devtools-proxy-support": "^0.5.1",
+    "@mongosh/arg-parser": "^3.14.0",
     "@mongosh/service-provider-node-driver": "^3.10.2",
     "@vitest/eslint-plugin": "^1.3.4",
     "bson": "^6.10.4",

package.json

@@ -1,9 +1,104 @@
 import path from "path";
 import os from "os";
 import argv from "yargs-parser";
-
+import type { CliOptions } from "@mongosh/arg-parser";
 import { ReadConcernLevel, ReadPreferenceMode, W } from "mongodb";
 
+// From: https://github.com/mongodb-js/mongosh/blob/main/packages/cli-repl/src/arg-parser.ts
+const OPTIONS = {
+    string: [
+        "apiBaseUrl",
+        "apiClientId",
+        "apiClientSecret",
+        "connectionString",
+        "httpHost",
+        "httpPort",
+        "idleTimeoutMs",
+        "logPath",
+        "notificationTimeoutMs",
+        "telemetry",
+        "transport",
+        "apiVersion",
+        "authenticationDatabase",
+        "authenticationMechanism",
+        "browser",
+        "db",
+        "gssapiHostName",
+        "gssapiServiceName",
+        "host",
+        "oidcFlows",
+        "oidcRedirectUri",
+        "password",
+        "port",
+        "sslCAFile",
+        "sslCRLFile",
+        "sslCertificateSelector",
+        "sslDisabledProtocols",
+        "sslPEMKeyFile",
+        "sslPEMKeyPassword",
+        "sspiHostnameCanonicalization",
+        "sspiRealmOverride",
+        "tlsCAFile",
+        "tlsCRLFile",
+        "tlsCertificateKeyFile",
+        "tlsCertificateKeyFilePassword",
+        "tlsCertificateSelector",
+        "tlsDisabledProtocols",
+        "username",
+    ],
+    boolean: [
+        "apiDeprecationErrors",
+        "apiStrict",
+        "help",
+        "indexCheck",
+        "ipv6",
+        "nodb",
+        "oidcIdTokenAsAccessToken",
+        "oidcNoNonce",
+        "oidcTrustedEndpoint",
+        "readOnly",
+        "retryWrites",
+        "ssl",
+        "sslAllowInvalidCertificates",
+        "sslAllowInvalidHostnames",
+        "sslFIPSMode",
+        "tls",
+        "tlsAllowInvalidCertificates",
+        "tlsAllowInvalidHostnames",
+        "tlsFIPSMode",
+        "tlsUseSystemCA",
+        "version",
+    ],
+    array: ["disabledTools", "loggers"],
+    alias: {
+        h: "help",
+        p: "password",
+        u: "username",
+        "build-info": "buildInfo",
+        browser: "browser",
+        oidcDumpTokens: "oidcDumpTokens",
+        oidcRedirectUrl: "oidcRedirectUri",
+        oidcIDTokenAsAccessToken: "oidcIdTokenAsAccessToken",
+    },
+    configuration: {
+        "camel-case-expansion": false,
+        "unknown-options-as-args": true,
+        "parse-positional-numbers": false,
+        "parse-numbers": false,
+        "greedy-arrays": true,
+        "short-option-groups": false,
+    },
+};
+
+function isConnectionSpecifier(arg: string | undefined): boolean {
+    return (
+        arg !== undefined &&
+        (arg.startsWith("mongodb://") ||
+            arg.startsWith("mongodb+srv://") ||
+            !(arg.endsWith(".js") || arg.endsWith(".mongodb")))
+    );
+}
+
 export interface ConnectOptions {
     readConcern: ReadConcernLevel;
     readPreference: ReadPreferenceMode;
@@ -13,7 +108,7 @@ export interface ConnectOptions {
 
 // If we decide to support non-string config options, we'll need to extend the mechanism for parsing
 // env variables.
-export interface UserConfig {
+export interface UserConfig extends CliOptions {
     apiBaseUrl: string;
     apiClientId?: string;
     apiClientSecret?: string;
@@ -53,11 +148,11 @@ const defaults: UserConfig = {
     notificationTimeoutMs: 540000, // 9 minutes
 };
 
-export const config = {
-    ...defaults,
-    ...getEnvConfig(),
-    ...getCliConfig(),
-};
+export const config = setupUserConfig({
+    defaults,
+    cli: process.argv,
+    env: process.env,
+});
 
 function getLogPath(): string {
     const localDataPath =
@@ -73,7 +168,7 @@ function getLogPath(): string {
 // Gets the config supplied by the user as environment variables. The variable names
 // are prefixed with `MDB_MCP_` and the keys match the UserConfig keys, but are converted
 // to SNAKE_UPPER_CASE.
-function getEnvConfig(): Partial<UserConfig> {
+function parseEnvConfig(env: Record<string, unknown>): Partial<UserConfig> {
     function setValue(obj: Record<string, unknown>, path: string[], value: string): void {
         const currentField = path.shift();
         if (!currentField) {
@@ -110,7 +205,7 @@ function getEnvConfig(): Partial<UserConfig> {
     }
 
     const result: Record<string, unknown> = {};
-    const mcpVariables = Object.entries(process.env).filter(
+    const mcpVariables = Object.entries(env).filter(
         ([key, value]) => value !== undefined && key.startsWith("MDB_MCP_")
     ) as [string, string][];
     for (const [key, value] of mcpVariables) {
@@ -129,9 +224,72 @@ function SNAKE_CASE_toCamelCase(str: string): string {
     return str.toLowerCase().replace(/([-_][a-z])/g, (group) => group.toUpperCase().replace("_", ""));
 }
 
-// Reads the cli args and parses them into a UserConfig object.
-function getCliConfig() {
-    return argv(process.argv.slice(2), {
-        array: ["disabledTools", "loggers"],
-    }) as unknown as Partial<UserConfig>;
+// Right now we have arguments that are not compatible with the format used in mongosh.
+// An example is using --connectionString and positional arguments.
+// We will consolidate them in a way where the mongosh format takes precedence.
+// We will warn users that previous configuration is deprecated in favour of
+// whatever is in mongosh.
+function parseCliConfig(args: string[]): CliOptions {
+    const programArgs = args.slice(2);
+    const parsed = argv(programArgs, OPTIONS) as unknown as CliOptions &
+        UserConfig & {
+            _?: string[];
+        };
+
+    const positionalArguments = parsed._ ?? [];
+    if (!parsed.nodb && isConnectionSpecifier(positionalArguments[0])) {
+        parsed.connectionSpecifier = positionalArguments.shift();
+    }
+
+    delete parsed._;
+    return parsed;
+}
+
+function commaSeparatedToArray<T extends string[]>(str: string | string[] | undefined): T {
+    if (str === undefined) {
+        return [] as unknown as T;
+    }
+
+    if (!Array.isArray(str)) {
+        return [str] as T;
+    }
+
+    if (str.length === 0) {
+        return str as T;
+    }
+
+    if (str.length === 1) {
+        if (str[0]?.indexOf(",") === -1) {
+            return str as T;
+        } else {
+            return str[0]?.split(",").map((e) => e.trim()) as T;
+        }
+    }
+
+    return str as T;
+}
+
+export function setupUserConfig({
+    cli,
+    env,
+    defaults,
+}: {
+    cli: string[];
+    env: Record<string, unknown>;
+    defaults: Partial<UserConfig>;
+}): UserConfig {
+    const userConfig: UserConfig = {
+        ...defaults,
+        ...parseEnvConfig(env),
+        ...parseCliConfig(cli),
+    } as UserConfig;
+
+    userConfig.disabledTools = commaSeparatedToArray(userConfig.disabledTools);
+    userConfig.loggers = commaSeparatedToArray(userConfig.loggers);
+
+    if (userConfig.connectionString && userConfig.connectionSpecifier) {
+        delete userConfig.connectionString;
+    }
+
+    return userConfig;
 }