commandeer_macros/
lib.rs

1use proc_macro::TokenStream;
2use quote::quote;
3use syn::{
4    Expr, Ident, ItemFn, Result,
5    parse::{Parse, ParseStream},
6    parse_macro_input, parse_quote,
7};
8
9struct CommandeerArgs {
10    mode: Ident,
11    commands: Vec<String>,
12}
13
14const RECORD: &str = "Record";
15const REPLAY: &str = "Replay";
16
17impl Parse for CommandeerArgs {
18    fn parse(input: ParseStream) -> Result<Self> {
19        let mut commands = vec![];
20
21        let ident: Ident = input.parse()?;
22
23        let mode = match ident.to_string().as_str() {
24            x if [RECORD, REPLAY].contains(&x) => Ident::new(x, proc_macro2::Span::call_site()),
25            _ => {
26                return Err(syn::Error::new(
27                    ident.span(),
28                    format!("Expected '{RECORD}' or '{REPLAY}'"),
29                ));
30            }
31        };
32
33        input.parse::<syn::Token![,]>()?;
34
35        while !input.is_empty() {
36            if input.peek(syn::LitStr) {
37                let lit: syn::LitStr = input.parse()?;
38
39                commands.push(lit.value());
40            } else {
41                return Err(input.error("Expected a command string"));
42            }
43
44            if input.peek(syn::Token![,]) {
45                input.parse::<syn::Token![,]>()?;
46            }
47        }
48
49        if commands.is_empty() {
50            return Err(syn::Error::new(
51                input.span(),
52                "Expected at least one command string",
53            ));
54        }
55
56        Ok(CommandeerArgs { mode, commands })
57    }
58}
59
60/// Procedural macro for setting up commandeer test environment
61///
62/// Usage: `#[commandeer(Record, "echo", "ls")]`
63///
64/// This expands to code that creates a Commandeer instance and mocks the specified commands
65#[proc_macro_attribute]
66pub fn commandeer(args: TokenStream, input: TokenStream) -> TokenStream {
67    let args = parse_macro_input!(args as CommandeerArgs);
68    let mut input_fn = parse_macro_input!(input as ItemFn);
69
70    let fn_name = &input_fn.sig.ident;
71
72    let test_file_name = format!("cmds_{fn_name}.json");
73
74    // Split by commas and parse each part
75
76    let mock_commands: Vec<Expr> = args
77        .commands
78        .iter()
79        .map(|cmd| {
80            parse_quote! {
81                commandeer.mock_command(#cmd)
82            }
83        })
84        .collect();
85
86    let mode = args.mode;
87
88    // Create the setup statements
89    let setup_stmts: Vec<syn::Stmt> = vec![parse_quote! {
90        let commandeer = commandeer_test::Commandeer::new(#test_file_name, commandeer_test::Mode::#mode);
91    }];
92
93    let mock_stmts: Vec<syn::Stmt> = mock_commands
94        .iter()
95        .map(|expr| {
96            parse_quote! {
97                #expr;
98            }
99        })
100        .collect();
101
102    // Prepend the setup code to the function body
103    let mut new_stmts = setup_stmts;
104    new_stmts.extend(mock_stmts);
105    new_stmts.extend(input_fn.block.stmts);
106
107    input_fn.block.stmts = new_stmts;
108
109    let body_str = quote!(#input_fn).to_string();
110
111    if body_str.contains("local_serial_core") {
112        return syn::Error::new_spanned(
113            input_fn.sig.fn_token,
114            "Out of order error. `commandeer` macro must be above the `serial_test` macro.",
115        )
116        .to_compile_error()
117        .into();
118    }
119
120    TokenStream::from(quote! { #input_fn })
121}
commandeer_macros/lib.rs

commandeer_macros/
lib.rs
