Help messages don't display the default values of options and positional arguments

v-next/hardhat-errors/src/descriptors.ts

@@ -404,7 +404,7 @@ Please double check your arguments.`,
     },
     INVALID_NAME: {
       number: 503,
-      messageTemplate: "Argument name {name} is invalid",
+      messageTemplate: `Argument name "{name}" is invalid. It must consist only of alphanumeric characters and cannot start with a number.`,
       websiteTitle: "Invalid argument name",
       websiteDescription: `One of your Hardhat or task argument names is invalid.
 

v-next/hardhat/src/internal/cli/helpers/utils.ts

@@ -1,4 +1,5 @@
 import type { ArgumentType } from "@ignored/hardhat-vnext-core/config";
+import type { ArgumentTypeToValueType } from "@ignored/hardhat-vnext-core/types/arguments";
 import type { GlobalOptionDefinitions } from "@ignored/hardhat-vnext-core/types/global-options";
 import type { Task } from "@ignored/hardhat-vnext-core/types/tasks";
 
@@ -10,6 +11,7 @@ interface ArgumentDescriptor {
   name: string;
   description: string;
   type?: ArgumentType;
+  defaultValue?: ArgumentTypeToValueType<ArgumentType>;
   isRequired?: boolean;
 }
 
@@ -67,14 +69,22 @@ export function parseOptions(task: Task): {
       name: toCommandLineOption(optionName),
       description: option.description,
       type: option.type,
+      ...(option.defaultValue !== undefined && {
+        defaultValue: option.defaultValue,
+      }),
     });
   }
 
-  for (const argument of task.positionalArguments) {
+  for (const { name, description, defaultValue } of task.positionalArguments) {
     positionalArguments.push({
-      name: argument.name,
-      description: argument.description,
-      isRequired: argument.defaultValue === undefined,
+      name,
+      description,
+      isRequired: defaultValue === undefined,
+      ...(defaultValue !== undefined && {
+        defaultValue: Array.isArray(defaultValue)
+          ? defaultValue.join(", ")
+          : defaultValue,
+      }),
     });
   }
 
@@ -96,9 +106,11 @@ export function getSection(
 ): string {
   return `\n${title}:\n\n${items
     .sort((a, b) => a.name.localeCompare(b.name))
-    .map(
-      ({ name, description }) => `  ${name.padEnd(namePadding)}${description}`,
-    )
+    .map(({ name, description, defaultValue }) => {
+      const defaultValueStr =
+        defaultValue !== undefined ? ` (default: ${defaultValue})` : "";
+      return `  ${name.padEnd(namePadding)}${description}${defaultValueStr}`;
+    })
     .join("\n")}\n`;
 }
 

v-next/hardhat/test/fixture-projects/cli/parsing/default-values/hardhat.config.ts

@@ -0,0 +1,32 @@
+import type { HardhatUserConfig } from "@ignored/hardhat-vnext-core/config";
+
+import { task } from "@ignored/hardhat-vnext-core/config";
+
+const customTask = task("test", "subtask")
+  .setAction(async () => {})
+  .addOption({
+    name: "opt",
+    description: "opt description",
+    defaultValue: "opt default value",
+  })
+  .addPositionalArgument({
+    name: "pos1",
+    description: "pos1 description",
+  })
+  .addPositionalArgument({
+    name: "pos2",
+    description: "pos2 description",
+    defaultValue: "pos2 default value",
+  })
+  .addVariadicArgument({
+    name: "var1",
+    description: "var1 description",
+    defaultValue: ["var1 default value 1", "var1 default value 2"],
+  })
+  .build();
+
+const config: HardhatUserConfig = {
+  tasks: [customTask],
+};
+
+export default config;

v-next/hardhat/test/internal/cli/helpers/utils.ts

@@ -173,6 +173,7 @@ describe("utils", function () {
             name: "anotherPositionalArgument",
             description: "Another example argument",
             isRequired: false,
+            defaultValue: "default",
           },
         ],
       });

v-next/hardhat/test/internal/cli/main.ts

@@ -244,24 +244,59 @@ To get help for a specific task run: npx hardhat <TASK> [SUBTASK] --help`;
     });
 
     describe("subtask help", function () {
-      useFixtureProject("cli/parsing/subtask-help");
+      describe("empty subtask", () => {
+        useFixtureProject("cli/parsing/subtask-help");
 
-      it("should print an help message for the task's subtask", async function () {
-        let lines: string = "";
+        it("should print an help message for the task's subtask", async function () {
+          let lines: string = "";
 
-        const command = "npx hardhat empty-task --help";
-        const cliArguments = command.split(" ").slice(2);
+          const command = "npx hardhat empty-task --help";
+          const cliArguments = command.split(" ").slice(2);
 
-        await main(cliArguments, (msg) => {
-          lines = msg;
-        });
+          await main(cliArguments, (msg) => {
+            lines = msg;
+          });
 
-        const expected = `${chalk.bold("empty task description")}
+          const expected = `${chalk.bold("empty task description")}
 
 Usage: hardhat [GLOBAL OPTIONS] empty-task <SUBTASK> [SUBTASK OPTIONS] [--] [SUBTASK POSITIONAL ARGUMENTS]
 `;
 
-        assert.equal(lines, expected);
+          assert.equal(lines, expected);
+        });
+      });
+
+      describe("task with default values", () => {
+        useFixtureProject("cli/parsing/default-values");
+
+        it("should print the default values for the task's subtask", async function () {
+          let lines: string = "";
+
+          const command = "npx hardhat test subtask --help";
+          const cliArguments = command.split(" ").slice(2);
+
+          await main(cliArguments, (msg) => {
+            lines = msg;
+          });
+
+          const expected = `${chalk.bold("subtask")}
+
+Usage: hardhat [GLOBAL OPTIONS] test [--opt <STRING>] [--] pos1 [pos2] [var1]
+
+OPTIONS:
+
+  --opt      opt description (default: opt default value)
+
+POSITIONAL ARGUMENTS:
+
+  pos1       pos1 description
+  pos2       pos2 description (default: pos2 default value)
+  var1       var1 description (default: var1 default value 1, var1 default value 2)
+
+For global options help run: hardhat --help`;
+
+          assert.equal(lines, expected);
+        });
       });
     });