Enhancement: More robustly handle help requests in Truffle

packages/core/cli.js

@@ -42,22 +42,38 @@ listeners.forEach(listener => process.removeListener("warning", listener));
 
 const inputStrings = process.argv.slice(2);
 
-const userWantsGeneralHelp =
-  inputStrings.length === 0 ||
-  (inputStrings.length === 1 && ["help", "--help"].includes(inputStrings[0]));
-
-if (userWantsGeneralHelp) {
-  const { displayGeneralHelp } = require("./lib/command-utils");
-  displayGeneralHelp();
-  process.exit(0);
-}
-
 const {
   getCommand,
   prepareOptions,
-  runCommand
+  runCommand,
+  displayGeneralHelp
 } = require("./lib/command-utils");
 
+//User only enter truffle with no commands, let's show them what's available.
+if (inputStrings.length === 0) {
+  displayGeneralHelp();
+  process.exit();
+}
+
+//if `help` or `--help` is in the command, validate and transform the input argument for help
+if (
+  inputStrings.some(inputString => ["help", "--help"].includes(inputString))
+) {
+  //when user wants general help
+  if (inputStrings.length === 1) {
+    displayGeneralHelp();
+    process.exit();
+  }
+
+  //check where is --help used, mutate argument into a proper help command
+  const helpIndex = inputStrings.indexOf("--help");
+
+  if (helpIndex !== -1) {
+    inputStrings.splice(helpIndex, 1);
+    inputStrings.unshift("help");
+  }
+}
+
 const command = getCommand({
   inputStrings,
   options: {},
@@ -67,7 +83,9 @@ const command = getCommand({
 //getCommand() will return null if a command not recognized by truffle is used.
 if (command === null) {
   console.log(
-    `\`truffle ${inputStrings}\` is not a valid truffle command. Please see \`truffle help\` for available commands.`
+    `\`truffle ${inputStrings.join(
+      " "
+    )}\` is not a valid truffle command. Please see \`truffle help\` for available commands.`
   );
   process.exit(1);
 }

packages/core/lib/command-utils.js

@@ -93,8 +93,10 @@ const prepareOptions = ({ command, inputStrings, options }) => {
   const yargs = require("yargs/yargs")();
   yargs
     .command(require(`./commands/${command.name}/meta`))
-    //Turn off yargs' default behavior when handling "truffle --version"
-    .version(false);
+    //Turn off yargs' default behavior when handling `truffle --version` & `truffle <cmd> --help`
+    .version(false)
+    .help(false);
+
   const commandOptions = yargs.parse(inputStrings);
 
   // remove the task name itself put there by yargs

packages/core/lib/commands/db/run.js

@@ -13,6 +13,6 @@ module.exports = async function (args) {
       break;
 
     default:
-      console.log(`Unknown command: ${subCommand}`);
+      console.log(`Unknown truffle db command: ${subCommand}`);
   }
 };

packages/core/lib/commands/help/displayCommandHelp.js

@@ -1,12 +1,20 @@
 module.exports = async function (selectedCommand, subCommand, options) {
   const commands = require("../index");
   const globalCommandOptions = require("../../global-command-options");
+  const TruffleError = require("@truffle/error");
 
   let commandHelp, commandDescription;
 
+  const inputStrings = process.argv.slice(2);
+
   const chosenCommand = commands[selectedCommand].meta;
 
-  if (subCommand && chosenCommand.subCommands[subCommand]) {
+  if (subCommand) {
+    if (!chosenCommand.subCommands || !chosenCommand.subCommands[subCommand]) {
+      throw new TruffleError(
+        `"truffle ${inputStrings.join(" ")}" is an invalid command`
+      );
+    }
     commandHelp = chosenCommand.subCommands[subCommand].help;
     commandDescription = chosenCommand.subCommands[subCommand].description;
   } else {

packages/core/lib/commands/help/meta.js

@@ -1,9 +1,16 @@
+const OS = require("os");
+
 module.exports = {
   command: "help",
   description:
     "List all commands or provide information about a specific command",
   help: {
-    usage: "truffle help [<command>]",
+    usage:
+      "truffle help [<command> [<subCommand>]]" +
+      OS.EOL +
+      "                truffle --help [<command> [<subCommand>]]" +
+      OS.EOL +
+      "                truffle [<command> [<subCommand>]] --help",
     options: [
       {
         option: "<command>",

packages/core/package.json

@@ -35,6 +35,7 @@
     "@truffle/debugger": "^11.0.22",
     "@truffle/decoder": "^5.3.5",
     "@truffle/deployer": "^3.3.2",
+    "@truffle/db-loader": "^0.2.10",
     "@truffle/environment": "^0.2.135",
     "@truffle/error": "^0.2.0",
     "@truffle/expect": "^0.1.4",
@@ -69,6 +70,7 @@
     "get-random-values": "^1.2.2",
     "glob": "^7.1.6",
     "inquirer": "8.2.2",
+    "iter-tools": "^7.5.0",
     "js-interpreter": "2.2.0",
     "lodash": "^4.17.21",
     "mocha": "10.1.0",
@@ -82,6 +84,7 @@
     "universal-analytics": "^0.4.17",
     "web3": "1.8.1",
     "web3-utils": "1.8.1",
+    "uuid": "^9.0.0",
     "xregexp": "^4.2.4",
     "yargs": "^13.3.0"
   },
@@ -103,4 +106,4 @@
     }
   ],
   "namespace": "consensys"
-}
+}

packages/truffle/test/scenarios/commands/help.js

@@ -42,5 +42,37 @@ describe("truffle help [ @standalone ]", function () {
       );
       assert(output.includes("--environment"));
     });
+
+    it("displays help for the `help` command", async function () {
+      await CommandRunner.run("help help", config);
+      const output = logger.contents();
+      assert(
+        output.includes(
+          " Description:  List all commands or provide information about a specific command"
+        )
+      );
+    }).timeout(20000);
+
+    it("displays help for given command when `--help` is at final position of the command line", async function () {
+      await CommandRunner.run("compile --help", config);
+      const output = logger.contents();
+      assert(output.includes("Description:  Compile contract source files"));
+    }).timeout(20000);
+
+    it("displays help for given command when `--help` is at first position of the command line", async function () {
+      await CommandRunner.run("--help db serve", config);
+      const output = logger.contents();
+      assert(
+        output.includes("Description:  Start Truffle's GraphQL UI playground")
+      );
+    }).timeout(20000);
+
+    it("displays help for given command when `--help` is in the middle of the command line", async function () {
+      await CommandRunner.run("db --help serve", config);
+      const output = logger.contents();
+      assert(
+        output.includes("Description:  Start Truffle's GraphQL UI playground")
+      );
+    }).timeout(20000);
   });
 });

yarn.lock

@@ -16659,6 +16659,13 @@ iter-tools@^7.0.2:
   dependencies:
     "@babel/runtime" "^7.12.1"
 
+iter-tools@^7.5.0:
+  version "7.5.0"
+  resolved "https://registry.yarnpkg.com/iter-tools/-/iter-tools-7.5.0.tgz#061240dcac13668e66bb787b0fcd407a58ea39ab"
+  integrity sha512-L0p/RG3Hwk1urilryDKqU8pQ1t5AaaMc7CHmiwJD/uh63Lv7VyjNng/esstf+Tct1587IpetpcDFdufz8sG+sQ==
+  dependencies:
+    "@babel/runtime" "^7.12.1"
+
 iterate-iterator@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/iterate-iterator/-/iterate-iterator-1.0.1.tgz#1693a768c1ddd79c969051459453f082fe82e9f6"