FileParser<T>

Trait used for parsing files in different formats, such as JSON and plain text.

trait FileParser<T, +Serde<T>> {
    fn parse_txt(file: @File) -> Option<T>;
    fn parse_json(file: @File) -> Option<T>;
}

ℹ️ Info

Specific rules must be followed for snforge to correctly parse JSON and plain text files.

Read file format rules for more.

Example

File content:

{
    "age": 30,
    "job": "Software Engineer",
    "location": {
        "city": "New York",
        "country": "USA"
    },
    "name": "John",
    "surname": "Doe"
}

Test code:

use core::array::ArrayTrait;
use core::option::OptionTrait;
use core::serde::Serde;
use snforge_std::fs::{FileParser, FileTrait};

#[derive(Debug, Serde, Drop, PartialEq)]
struct Location {
    city: ByteArray,
    country: ByteArray,
}

#[derive(Debug, Serde, Drop, PartialEq)]
struct User {
    age: u32,
    job: ByteArray,
    location: Location,
    name: ByteArray,
    surname: ByteArray,
}


#[test]
fn parse_json_example() {
    // Create an instance of `File` to be used later
    let file = FileTrait::new("data/user.json");

    // Parse the JSON content from the file
    let content = FileParser::<User>::parse_json(@file).expect('Failed to parse JSON');

    // Serialize the content to an array for comparison
    let mut output_array = ArrayTrait::new();
    content.serialize(ref output_array);

    println!("{:?}", content);

    assert!(content.name == "John");
    assert!(content.location.country == "USA");
    assert!(content.age == 30);
}

Let's run the test:

$ snforge test parse_json_example

Collected 1 test(s) from snforge_library_reference package
Running 1 test(s) from tests/
User { age: 30, job: "Software Engineer", location: Location { city: "New York", country: "USA" }, name: "John", surname: "Doe" }
[PASS] snforge_library_reference_integrationtest::test_fs_parse_json::parse_json_example ([..])
Running 0 test(s) from src/
Tests: 1 passed, 0 failed, 0 ignored, [..] filtered out