Function expand

assert-struct-macros/src/expand.rs:18–73

(assert: &AssertStruct)

use nodes::{expand_pattern_node_ident, generate_pattern_nodes};

pub fn expand(assert: &AssertStruct) -> TokenStream {
    let value = &assert.value;
    let pattern = &assert.pattern;

    // Generate pattern nodes using the node IDs from the patterns
    let mut node_defs = Vec::new();
    let root_ref = generate_pattern_nodes(pattern, &mut node_defs, None);

    // Generate static declarations for all nodes
    let node_constants: Vec<TokenStream> = node_defs
        .iter()
        .map(|(id, def)| {
            let ident = Ident::new(&format!("__PATTERN_NODE_{}", id), Span::call_site());
            quote! {
                static #ident: ::assert_struct::__macro_support::PatternNode = #def;
            }
        })
        .collect();

    let assertion = expand_pattern_assertion(&quote! { #value }, pattern);

    // Wrap in a block to avoid variable name conflicts
    quote! {
        {
            // Suppress clippy warnings that are expected in macro-generated code
            #[allow(unused_assignments, clippy::neg_cmp_op_on_partial_ord, clippy::op_ref, clippy::zero_prefixed_literal, clippy::bool_comparison, clippy::redundant_pattern_matching, clippy::useless_asref)]
            let __assert_struct_result = {
                use std::convert::AsRef;

                // Generate all node constants
                #(#node_constants)*

                // Store the pattern tree root
                const __PATTERN_TREE: &::assert_struct::__macro_support::PatternNode = &#root_ref;

                // Create error report. Both values are compile-time constants:
                // - CARGO_MANIFEST_DIR: absolute path to this package's root
                // - file!(): path relative to the workspace root
                // Together they let us derive the absolute source path at runtime
                // without relying on the working directory.
                let mut __report = ::assert_struct::__macro_support::ErrorReport::new(
                    ::std::env!("CARGO_MANIFEST_DIR"),
                    ::std::file!(),
                );

                #assertion

                // Check if any errors were collected
                if !__report.is_empty() {
                    panic!("{}", __report);
                }
            };
            __assert_struct_result
        }
    }
}

/// Generate assertion code with error collection instead of immediate panic.