feat(flags,command): add did-you-mean support and improve error messa…

…ges (#131)

command/README.md

@@ -184,7 +184,7 @@ console.log(options);
 
 ```
 $ deno run https://deno.land/x/cliffy/examples/command/common_option_types.ts -p
-Error: Missing value for option: --pizza-type
+Error: Missing value for option "--pizza-type".
 
 $ deno run https://deno.land/x/cliffy/examples/command/common_option_types.ts -sp vegetarian --amount 3
 { small: true, pizzaType: "vegetarian", amount: 3 }
@@ -472,7 +472,7 @@ $ deno run https://deno.land/x/cliffy/examples/command/depending_options.ts -a a
 { audioCodec: "aac" }
 
 $ deno run https://deno.land/x/cliffy/examples/command/depending_options.ts -v x265
-Option --video-codec depends on option: --audio-codec
+Error: Option "--video-codec" depends on option "--audio-codec".
 
 $ deno run https://deno.land/x/cliffy/examples/command/depending_options.ts -a aac -v x265
 { audioCodec: "aac", videoCodec: "x265" }
@@ -521,7 +521,7 @@ const { options } = await new Command()
     value: (value: string, previous: string[] = []): string[] => {
       if (["blue", "yellow", "red"].indexOf(value) === -1) {
         throw new Error(
-          `Color must be one of blue, yellow or red but got: ${value}`,
+          `Color must be one of "blue, yellow or red", but got "${value}".`,
         );
       }
       previous.push(value);
@@ -837,7 +837,7 @@ try {
 
 ```textile
 $ deno run https://deno.land/x/cliffy/examples/command/override_exit_handling.ts -t
-[CUSTOM_ERROR] Error: Unknown option: -t
+[CUSTOM_ERROR] Error: Unknown option "-t".
 ```
 
 ## ❯ Custom types
@@ -857,7 +857,7 @@ const emailRegex =
 
 function emailType({ label, name, value }: ITypeInfo): string {
   if (!emailRegex.test(value.toLowerCase())) {
-    throw new Error(`${label} ${name} must be a valid email but got: ${value}`);
+    throw new Error(`${label} "${name}" must be a valid "email", but got "${value}".`);
   }
 
   return value;
@@ -878,7 +878,7 @@ $ deno run https://deno.land/x/cliffy/examples/command/custom_option_type.ts -e
 
 ```
 $ deno run https://deno.land/x/cliffy/examples/command/custom_option_type.ts -e "my @email.com"
-Option --email must be a valid email but got: my @email.com
+Error: Option "--email" must be a valid "email", but got "my @email.com".
 ```
 
 ### Class types
@@ -896,7 +896,7 @@ class EmailType extends Type<string> {
   public parse({ label, name, value }: ITypeInfo): string {
     if (!this.emailRegex.test(value.toLowerCase())) {
       throw new Error(
-        `${label} ${name} must be a valid email but got: ${value}`,
+        `${label} "${name}" must be a valid "email", but got "${value}".`,
       );
     }
 
@@ -919,7 +919,7 @@ $ deno run https://deno.land/x/cliffy/examples/command/custom_option_type_class.
 
 ```
 $ deno run https://deno.land/x/cliffy/examples/command/custom_option_type_class.ts -e "my @email.de"
-Option --email must be a valid email but got: my @email.de
+Error: Option "--email" must be a valid "email", but got "my @email.de".
 ```
 
 ### Global types
@@ -976,7 +976,7 @@ $ SOME_ENV_VAR=1 deno run --allow-env --unstable https://deno.land/x/cliffy/exam
 1
 
 $ SOME_ENV_VAR=abc deno run --allow-env --unstable https://deno.land/x/cliffy/examples/command/environment_variables.ts
-Error: Environment variable SOME_ENV_VAR must be of type number but got: abc
+Error: Environment variable "SOME_ENV_VAR" must be of type "number", but got "abc".
 ```
 
 ## ❯ Add examples

command/_arguments_parser.ts

@@ -69,7 +69,7 @@ export class ArgumentsParser {
 
       if (!details.optionalValue && hasOptional) {
         throw new Error(
-          "An required argument can not follow an optional argument.",
+          `An required argument can not follow an optional argument but "${details.name}" is defined as required.`,
         );
       }
 

command/command.ts

@@ -1,3 +1,4 @@
+import { didYouMean, didYouMeanType } from "../flags/_utils.ts";
 import { parseFlags } from "../flags/flags.ts";
 import type { IFlagsResult } from "../flags/types.ts";
 import { existsSync, red } from "./deps.ts";
@@ -221,7 +222,7 @@ export class Command<O = any, A extends Array<any> = any> {
 
     if (this.getBaseCommand(name, true)) {
       if (!override) {
-        throw this.error(new Error(`Duplicate command: ${name}`));
+        throw this.error(new Error(`Duplicate command "${name}".`));
       }
       this.removeCommand(name);
     }
@@ -284,12 +285,12 @@ export class Command<O = any, A extends Array<any> = any> {
   public alias(alias: string): this {
     if (this.cmd === this) {
       throw this.error(
-        new Error(`Failed to add alias '${alias}'. No sub command selected.`),
+        new Error(`Failed to add alias "${alias}". No sub command selected.`),
       );
     }
 
     if (this.cmd.aliases.indexOf(alias) !== -1) {
-      throw this.error(new Error(`Duplicate alias: ${alias}`));
+      throw this.error(new Error(`Duplicate alias "${alias}".`));
     }
 
     this.cmd.aliases.push(alias);
@@ -310,7 +311,13 @@ export class Command<O = any, A extends Array<any> = any> {
     const cmd = this.getBaseCommand(name, true);
 
     if (!cmd) {
-      throw this.error(new Error(`Sub-command not found: ${name}`));
+      throw this.error(
+        new Error(
+          `Unknown sub-command "${name}".${
+            didYouMeanCommand(name, this.getBaseCommands(true))
+          }`,
+        ),
+      );
     }
 
     this.cmd = cmd;
@@ -446,7 +453,7 @@ export class Command<O = any, A extends Array<any> = any> {
     options?: ITypeOptions,
   ): this {
     if (this.cmd.types.get(name) && !options?.override) {
-      throw this.error(new Error(`Type '${name}' already exists.`));
+      throw this.error(new Error(`Type with name "${name}" already exists.`));
     }
 
     this.cmd.types.set(name, { ...options, name, handler });
@@ -475,7 +482,9 @@ export class Command<O = any, A extends Array<any> = any> {
     options?: ICompleteOptions,
   ): this {
     if (this.cmd.completions.has(name) && !options?.override) {
-      throw this.error(new Error(`Completion '${name}' already exists.`));
+      throw this.error(
+        new Error(`Completion with name "${name}" already exists.`),
+      );
     }
 
     this.cmd.completions.set(name, {
@@ -549,7 +558,9 @@ export class Command<O = any, A extends Array<any> = any> {
       if (
         option.name === name || option.aliases && ~option.aliases.indexOf(name)
       ) {
-        throw this.error(new Error(`Duplicate command name: ${name}`));
+        throw this.error(
+          new Error(`Command with name "${name}" already exists.`),
+        );
       }
 
       if (!option.name && isLong) {
@@ -564,7 +575,9 @@ export class Command<O = any, A extends Array<any> = any> {
         if (opts?.override) {
           this.removeOption(name);
         } else {
-          throw this.error(new Error(`Duplicate option name: ${name}`));
+          throw this.error(
+            new Error(`Option with name "${name}" already exists.`),
+          );
         }
       }
     }
@@ -585,7 +598,9 @@ export class Command<O = any, A extends Array<any> = any> {
    */
   public example(name: string, description: string): this {
     if (this.cmd.hasExample(name)) {
-      throw this.error(new Error("Example already exists."));
+      throw this.error(
+        new Error(`Example with name "${name}" already exists.`),
+      );
     }
 
     this.cmd.examples.push({ name, description });
@@ -612,7 +627,7 @@ export class Command<O = any, A extends Array<any> = any> {
 
     if (result.flags.some((envName) => this.cmd.getBaseEnvVar(envName, true))) {
       throw this.error(
-        new Error(`Environment variable already exists: ${name}`),
+        new Error(`Environment variable with name "${name}" already exists.`),
       );
     }
 
@@ -623,19 +638,19 @@ export class Command<O = any, A extends Array<any> = any> {
     if (details.length > 1) {
       throw this.error(
         new Error(
-          `An environment variable can only have one value but got: ${name}`,
+          `An environment variable can only have one value but "${name}" has more than one.`,
         ),
       );
     } else if (details.length && details[0].optionalValue) {
       throw this.error(
         new Error(
-          `An environment variable can not have an optional value but '${name}' is defined as optional.`,
+          `An environment variable can not have an optional value but "${name}" is defined as optional.`,
         ),
       );
     } else if (details.length && details[0].variadic) {
       throw this.error(
         new Error(
-          `An environment variable can not have an variadic value but '${name}' is defined as variadic.`,
+          `An environment variable can not have an variadic value but "${name}" is defined as variadic.`,
         ),
       );
     }
@@ -664,6 +679,8 @@ export class Command<O = any, A extends Array<any> = any> {
     args: string[] = Deno.args,
     dry?: boolean,
   ): Promise<IParseResult<O, A>> {
+    // @TODO: remove all `this.error()` calls and catch errors only in parse method!
+
     this.reset()
       .registerDefaults();
 
@@ -791,7 +808,11 @@ export class Command<O = any, A extends Array<any> = any> {
 
       if (!cmd) {
         throw this.error(
-          new Error(`Default command '${this.defaultCommand}' not found.`),
+          new Error(
+            `Default command "${this.defaultCommand}" not found.${
+              didYouMeanCommand(this.defaultCommand, this.getCommands())
+            }`,
+          ),
         );
       }
 
@@ -920,7 +941,13 @@ export class Command<O = any, A extends Array<any> = any> {
     const typeSettings: IType | undefined = this.getType(type.type);
 
     if (!typeSettings) {
-      throw this.error(new Error(`No type registered with name: ${type.type}`));
+      throw this.error(
+        new Error(
+          `Unknown type "${type.type}".${
+            didYouMeanType(type.type, this.getTypes().map((type) => type.name))
+          }`,
+        ),
+      );
     }
 
     return typeSettings.handler instanceof Type
@@ -967,10 +994,16 @@ export class Command<O = any, A extends Array<any> = any> {
     if (!this.hasArguments()) {
       if (args.length) {
         if (this.hasCommands(true)) {
-          throw this.error(new Error(`Unknown command: ${args.join(" ")}`));
+          throw this.error(
+            new Error(
+              `Unknown command "${args[0]}".${
+                didYouMeanCommand(args[0], this.getCommands())
+              }`,
+            ),
+          );
         } else {
           throw this.error(
-            new Error(`No arguments allowed for command: ${this.getPath()}`),
+            new Error(`No arguments allowed for command "${this.getPath()}".`),
           );
         }
       }
@@ -1755,3 +1788,14 @@ function isDebug(): boolean {
   const debug: string | undefined = Deno.env.get("CLIFFY_DEBUG");
   return debug === "true" || debug === "1";
 }
+
+export function didYouMeanCommand(
+  command: string,
+  commands: Array<Command>,
+  excludes: Array<string> = [],
+): string {
+  const commandNames = commands
+    .map((command) => command.getName())
+    .filter((command) => !excludes.includes(command));
+  return didYouMean(" Did you mean command", command, commandNames);
+}

command/completions/complete.ts

@@ -1,4 +1,4 @@
-import { Command } from "../command.ts";
+import { Command, didYouMeanCommand } from "../command.ts";
 import type { ICompletion } from "../types.ts";
 
 /** Execute auto completion method of command and action. */
@@ -20,8 +20,8 @@ export class CompleteCommand extends Command {
               const childCmd: Command | undefined = cmd.getCommand(name, false);
               if (!childCmd) {
                 throw new Error(
-                  `Auto-completion failed. Command not found: ${
-                    commandNames.join(" ")
+                  `Auto-completion failed. Unknown command "${name}".${
+                    didYouMeanCommand(name, cmd.getCommands())
                   }`,
                 );
               }

command/help/_help_generator.ts

@@ -1,3 +1,4 @@
+import { getFlag } from "../../flags/_utils.ts";
 import { Table } from "../../table/table.ts";
 import { ArgumentsParser } from "../_arguments_parser.ts";
 import type { Command } from "../command.ts";
@@ -231,13 +232,3 @@ function inspect(value: unknown): string {
     { depth: 1, colors: true, trailingComma: false } as Deno.InspectOptions,
   );
 }
-
-function getFlag(name: string) {
-  if (name.startsWith("-")) {
-    return name;
-  }
-  if (name.length > 1) {
-    return `--${name}`;
-  }
-  return `-${name}`;
-}

command/help/mod.ts

@@ -1,4 +1,4 @@
-import { Command } from "../command.ts";
+import { Command, didYouMeanCommand } from "../command.ts";
 import { CommandType } from "../types/command.ts";
 
 /** Generates well formatted and colored help output for specified command. */
@@ -15,8 +15,16 @@ export class HelpCommand extends Command {
             : this.getGlobalParent();
         }
         if (!cmd) {
+          const cmds = this.getGlobalParent()?.getCommands();
           throw new Error(
-            `Failed to generate help for command '${name}'. Command not found.`,
+            `Unknown command "${name}".${
+              name && cmds
+                ? didYouMeanCommand(name, cmds, [
+                  this.getName(),
+                  ...this.getAliases(),
+                ])
+                : ""
+            }`,
           );
         }
         cmd.help();

command/test/command/arguments_test.ts

@@ -8,7 +8,7 @@ function cmd() {
     .type("color", ({ label, name, type, value }: ITypeInfo) => {
       if (!["red", "blue", "yellow"].includes(value)) {
         throw new Error(
-          `${label} ${name} must be a valid ${type} but got: ${value}`,
+          `${label} "${name}" must be a valid "${type}", but got "${value}".`,
         );
       }
       return value;
@@ -34,7 +34,7 @@ Deno.test("invalid number command argument type", async () => {
       await cmd().parse(["abc", "xyz", "true", "red"]);
     },
     Error,
-    "Argument bar must be of type number but got: xyz",
+    `Argument "bar" must be of type "number", but got "xyz".`,
   );
 });
 
@@ -54,7 +54,7 @@ Deno.test("invalid boolean command argument type", async () => {
       await cmd().parse(["abc", "123", "xyz", "red"]);
     },
     Error,
-    "Argument baz must be of type boolean but got: xyz",
+    `Argument "baz" must be of type "boolean", but got "xyz".`,
   );
 });
 
@@ -64,6 +64,6 @@ Deno.test("invalid custom command argument type", async () => {
       await cmd().parse(["abc", "123", "true", "xyz"]);
     },
     Error,
-    "Argument color must be a valid color but got: xyz",
+    `Argument "color" must be a valid "color", but got "xyz".`,
   );
 });