nipdf-test-macro 0.1.1

#![allow(clippy::unwrap_used)]

use glob::glob;
use itertools::Itertools;
use proc_macro::TokenStream;
use quote::quote;
use std::{env::var, path::PathBuf};

/// Glob `*.pdf`, `*.pdf.link` files in `sample_files`, `../pdf/`, `pdf.js/test/pdfs` directories,
/// relative to crate directory.
/// for each file generate a test, using `#[test-case]` attribute.
/// For example: `#[test_case("sample_files/normal/foo.pdf")]`
///
/// To save compile time, file list cached in `${workspace}/target/render-test.list` file, if file
/// not exist, it will re-generated by directories. Each line in cache file is a file path.
///
/// Using `proc-macro2`, `syn`, `quote` crates to help for parsing and generating code.
#[proc_macro_attribute]
pub fn pdf_file_test_cases(_attr: TokenStream, item: TokenStream) -> TokenStream {
    let dirs = vec![
        "../nipdf/sample_files",
        "../../pdf",
        "../nipdf/pdf.js/test/pdfs",
    ];
    let patterns = vec!["**/*.pdf", "**/*.pdf.link"];
    let files = dirs
        .into_iter()
        .cartesian_product(patterns)
        .flat_map(|(dir, pattern)| {
            let dir: PathBuf = [&var("CARGO_MANIFEST_DIR").unwrap(), dir, pattern]
                .iter()
                .collect();
            glob(dir.to_str().unwrap())
                .unwrap()
                .map(|p| p.unwrap().to_str().unwrap().to_owned())
        })
        .collect_vec();

    let mut test_case_attrs = Vec::with_capacity(files.len());
    for file in files {
        let test_case_attr = quote! {
            #[test_case(#file)]
        };
        test_case_attrs.push(test_case_attr);
    }

    let input = syn::parse_macro_input!(item as syn::ItemFn);
    let tokens = quote! {
        #(#test_case_attrs)*
        #input
    };
    tokens.into()
}