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Merged
merged 2 commits into from
Aug 19, 2025
Merged

Add custom error class #398

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964404d
Add custom ParseError class
blakeembrey Aug 19, 2025
667d91f
Rename to PathError
blakeembrey Aug 19, 2025
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66 changes: 39 additions & 27 deletions src/index.spec.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -6,6 +6,7 @@ import {
stringify,
pathToRegexp,
TokenData,
ParseError,
} from "./index.js";
import {
PARSER_TESTS,
Expand All @@ -18,44 +19,65 @@ import {
* Dynamically generate the entire test suite.
*/
describe("path-to-regexp", () => {
describe("ParseError", () => {
it("should contain original path and debug url", () => {
const error = new ParseError(
"Unexpected END at index 7, expected }",
"/{:foo,",
);

expect(error).toBeInstanceOf(TypeError);
expect(error.message).toBe(
"Unexpected END at index 7, expected }: /{:foo,; visit https://git.new/pathToRegexpError for info",
);
expect(error.originalPath).toBe("/{:foo,");
});

it("should omit original url when undefined", () => {
const error = new ParseError(
"Unexpected END at index 7, expected }",
undefined,
);

expect(error).toBeInstanceOf(TypeError);
expect(error.message).toBe(
"Unexpected END at index 7, expected }; visit https://git.new/pathToRegexpError for info",
);
expect(error.originalPath).toBeUndefined();
});
});

describe("parse errors", () => {
it("should throw on unbalanced group", () => {
expect(() => parse("/{:foo,")).toThrow(
new TypeError(
"Unexpected END at index 7, expected }: /{:foo,; visit https://git.new/pathToRegexpError for info",
),
new ParseError("Unexpected END at index 7, expected }", "/{:foo,"),
);
});

it("should throw on nested unbalanced group", () => {
expect(() => parse("/{:foo/{x,y}")).toThrow(
new TypeError(
"Unexpected END at index 12, expected }: /{:foo/{x,y}; visit https://git.new/pathToRegexpError for info",
new ParseError(
"Unexpected END at index 12, expected }",
"/{:foo/{x,y}",
),
);
});

it("should throw on missing param name", () => {
expect(() => parse("/:/")).toThrow(
new TypeError(
"Missing parameter name at index 2: /:/; visit https://git.new/pathToRegexpError for info",
),
new ParseError("Missing parameter name at index 2", "/:/"),
);
});

it("should throw on missing wildcard name", () => {
expect(() => parse("/*/")).toThrow(
new TypeError(
"Missing parameter name at index 2: /*/; visit https://git.new/pathToRegexpError for info",
),
new ParseError("Missing parameter name at index 2", "/*/"),
);
});

it("should throw on unterminated quote", () => {
expect(() => parse('/:"foo')).toThrow(
new TypeError(
'Unterminated quote at index 2: /:"foo; visit https://git.new/pathToRegexpError for info',
),
new ParseError("Unterminated quote at index 2", '/:"foo'),
);
});
});
Expand Down Expand Up @@ -105,9 +127,7 @@ describe("path-to-regexp", () => {
describe("pathToRegexp errors", () => {
it("should throw when missing text between params", () => {
expect(() => pathToRegexp("/:foo:bar")).toThrow(
new TypeError(
'Missing text before "bar": /:foo:bar; visit https://git.new/pathToRegexpError for info',
),
new ParseError('Missing text before "bar" param', "/:foo:bar"),
);
});

Expand All @@ -119,11 +139,7 @@ describe("path-to-regexp", () => {
{ type: "param", name: "b" },
]),
),
).toThrow(
new TypeError(
'Missing text before "b"; visit https://git.new/pathToRegexpError for info',
),
);
).toThrow(new ParseError('Missing text before "b" param', undefined));
});

it("should throw with `originalPath` when missing text between params using TokenData", () => {
Expand All @@ -137,11 +153,7 @@ describe("path-to-regexp", () => {
"/[a][b]",
),
),
).toThrow(
new TypeError(
'Missing text before "b": /[a][b]; visit https://git.new/pathToRegexpError for info',
),
);
).toThrow(new ParseError('Missing text before "b" param', "/[a][b]"));
});

it("should contain the error line", () => {
Expand Down
47 changes: 23 additions & 24 deletions src/index.ts
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,6 @@ const DEFAULT_DELIMITER = "/";
const NOOP_VALUE = (value: string) => value;
const ID_START = /^[$_\p{ID_Start}]$/u;
const ID_CONTINUE = /^[$\u200c\u200d\p{ID_Continue}]$/u;
const DEBUG_URL = "https://git.new/pathToRegexpError";

/**
* Encode a string into another string.
Expand Down Expand Up @@ -112,16 +111,6 @@ function escape(str: string) {
return str.replace(/[.+*?^${}()[\]|/\\]/g, "\\$&");
}

/**
* Format error so it's easier to debug.
*/
function errorMessage(text: string, originalPath: string | undefined) {
let message = text;
if (originalPath !== undefined) message += `: ${originalPath}`;
message += `; visit ${DEBUG_URL} for info`;
return message;
}

/**
* Plain text.
*/
Expand Down Expand Up @@ -179,6 +168,21 @@ export class TokenData {
) {}
}

/**
* ParseError is thrown when there is an error processing the path.
*/
export class ParseError extends TypeError {
constructor(
message: string,
public readonly originalPath: string | undefined,
) {
let text = message;
if (originalPath) text += `: ${originalPath}`;
text += `; visit https://git.new/pathToRegexpError for info`;
super(text);
}
}

/**
* Parse a string for the raw tokens.
*/
Expand Down Expand Up @@ -215,16 +219,12 @@ export function parse(str: string, options: ParseOptions = {}): TokenData {
}

if (pos) {
throw new TypeError(
errorMessage(`Unterminated quote at index ${pos}`, str),
);
throw new ParseError(`Unterminated quote at index ${pos}`, str);
}
}

if (!value) {
throw new TypeError(
errorMessage(`Missing parameter name at index ${index}`, str),
);
throw new ParseError(`Missing parameter name at index ${index}`, str);
}

return value;
Expand Down Expand Up @@ -292,11 +292,9 @@ export function parse(str: string, options: ParseOptions = {}): TokenData {
continue;
}

throw new TypeError(
errorMessage(
`Unexpected ${type} at index ${index}, expected ${endType}`,
str,
),
throw new ParseError(
`Unexpected ${type} at index ${index}, expected ${endType}`,
str,
);
}

Expand Down Expand Up @@ -564,8 +562,9 @@ function toRegExpSource(

if (token.type === "param" || token.type === "wildcard") {
if (!isSafeSegmentParam && !backtrack) {
throw new TypeError(
errorMessage(`Missing text before "${token.name}"`, originalPath),
throw new ParseError(
`Missing text before "${token.name}" ${token.type}`,
originalPath,
);
}

Expand Down