Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

fix: parsing decimals and scientific notation #94

Merged
merged 1 commit into from
Oct 24, 2023
Merged

fix: parsing decimals and scientific notation #94

Show file tree
Hide file tree
Changes from all commits
Commits
Show all changes
1 commit
Select commit
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
2 changes: 1 addition & 1 deletion src/index.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -5,7 +5,7 @@ const suspectProtoRx =
const suspectConstructorRx =
/"(?:c|\\u0063)(?:o|\\u006[Ff])(?:n|\\u006[Ee])(?:s|\\u0073)(?:t|\\u0074)(?:r|\\u0072)(?:u|\\u0075)(?:c|\\u0063)(?:t|\\u0074)(?:o|\\u006[Ff])(?:r|\\u0072)"\s*:/;

const JsonSigRx = /^\s*["[{]|^\s*-?\d[\d.]{0,14}\s*$/;
const JsonSigRx = /^\s*["[{]|^\s*-?\d{1,16}(\.\d{1,17})?([Ee][+-]?\d+)?\s*$/;
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

There is only a small issue with this. It seems maximum 16 digits cannot be combined with 17 decimal places at the same time. So 1.1234567812345678 is valid (well, kinda it will rounded to 1.1234567812345677) also 1234567812345678 is valid but 1234567812345678.1234567812345678 will be trimmed to 1234567812345678.

I don't think for this particular regex it would be an issue because JSON.parse will normalize it anyway...

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Yes, the regex here are slightly rough, and being able to cover all the right scenarios should be enough, leaving the rest to JSON.parse

Copy link
Contributor Author

@kricsleo kricsleo Oct 25, 2023 •
edited

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

@pi0 Sorry to disturb, I ran into a new problem today, in nodejs numbers can have more than 17 decimals (Math.random() gave me this result 0.018178923413311843), so in order to cover more scenarios, can we remove the digit limit and just match with more than 1 digit, for example:

- const JsonSigRx = /^\s*["[{]|^\s*-?\d{1,16}(\.\d{1,17})?([Ee][+-]?\d+)?\s*$/;
+ const JsonSigRx = /^\s*["[{]|^\s*-?\d+(\.\d+)?([Ee][+-]?\d+)?\s*$/;


function jsonParseTransform(key: string, value: any): any {
if (
Expand Down
18 changes: 18 additions & 0 deletions test/index.test.ts
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -178,4 +178,22 @@ describe("destr", () => {
);
}
});

it("parses number", () => {
const testCases: Array<{ input: string; output: unknown }> = [
{ input: "9", output: 9 },
{ input: "-9", output: -9 },
{ input: "0.30000000000000004", output: 0.300_000_000_000_000_04 },
{ input: "9007199254740991", output: 9_007_199_254_740_991 },
{ input: "9e2", output: 900 },
{ input: "9e+2", output: 900 },
{ input: "9e-2", output: 0.09 },
{ input: "9.9e10000", output: Number.POSITIVE_INFINITY },
{ input: "9.9e-10000", output: 0 },
];

for (const testCase of testCases) {
expect(destr(testCase.input)).toStrictEqual(testCase.output);
}
});
});