test: Add proc macro DSL for declarative tests.

This commit is contained in:
2026-03-13 21:58:17 -04:00
parent cb7911e5c9
commit 522b9f2894
4 changed files with 1103 additions and 0 deletions

View File

@@ -0,0 +1,428 @@
use proc_macro2::Span;
use syn::{
Ident, LitInt, LitStr, Token, braced, bracketed,
parse::{Parse, ParseStream},
};
// ---------------------------------------------------------------------------
// AST types
// ---------------------------------------------------------------------------
pub struct PiklTests {
pub modules: Vec<TestModule>,
}
pub struct TestModule {
pub kind: TestKind,
pub name: Ident,
pub fixtures: Fixtures,
pub tests: Vec<TestCase>,
}
#[derive(Clone, Copy, PartialEq, Eq)]
pub enum TestKind {
Headless,
Filter,
Nav,
Menu,
}
pub struct Fixtures {
pub items: Option<Vec<String>>,
pub label_key: Option<String>,
pub viewport: Option<(usize, usize)>, // (height, count)
}
pub struct TestCase {
pub name: Ident,
pub actions: Vec<ActionExpr>,
pub stdout: Option<String>,
pub stderr_contains: Option<String>,
pub exit_code: Option<i32>,
pub query: Option<String>,
pub match_labels: Option<Vec<String>>,
pub cursor: Option<usize>,
pub offset: Option<usize>,
pub selected: Option<String>,
pub cancelled: bool,
}
pub enum ActionExpr {
/// A simple action like "confirm", "cancel", "move-down".
Simple(String),
/// `filter "query text"`
Filter(String),
/// `raw "literal script line"`
Raw(String),
/// `add-items ["a", "b", "c"]`
AddItems(Vec<String>),
}
// ---------------------------------------------------------------------------
// Top-level parse
// ---------------------------------------------------------------------------
impl Parse for PiklTests {
fn parse(input: ParseStream) -> syn::Result<Self> {
let mut modules = Vec::new();
while !input.is_empty() {
modules.push(input.parse()?);
}
Ok(PiklTests { modules })
}
}
// ---------------------------------------------------------------------------
// Module parse
// ---------------------------------------------------------------------------
impl Parse for TestModule {
fn parse(input: ParseStream) -> syn::Result<Self> {
let kind = parse_kind(input)?;
input.parse::<Token![mod]>()?;
let name: Ident = input.parse()?;
let content;
braced!(content in input);
let mut fixtures = Fixtures {
items: None,
label_key: None,
viewport: None,
};
let mut tests = Vec::new();
while !content.is_empty() {
// Peek at the next identifier to decide what we're parsing.
let fork = content.fork();
let ident_str = parse_ident_or_keyword(&fork)?;
match ident_str.as_str() {
"test" => {
tests.push(parse_test_case(&content)?);
}
"items" => {
consume_ident_or_keyword(&content)?;
content.parse::<Token![:]>()?;
fixtures.items = Some(parse_string_list(&content)?);
eat_semi(&content);
}
"label_key" => {
consume_ident_or_keyword(&content)?;
content.parse::<Token![:]>()?;
let val: LitStr = content.parse()?;
fixtures.label_key = Some(val.value());
eat_semi(&content);
}
"viewport" => {
consume_ident_or_keyword(&content)?;
content.parse::<Token![:]>()?;
fixtures.viewport = Some(parse_viewport_def(&content)?);
eat_semi(&content);
}
_ => {
return Err(syn::Error::new(
content.span(),
format!(
"unexpected field '{ident_str}', expected test, items, label_key, or viewport"
),
));
}
}
}
Ok(TestModule {
kind,
name,
fixtures,
tests,
})
}
}
// ---------------------------------------------------------------------------
// Test case parse
// ---------------------------------------------------------------------------
/// Parse a single `test name { ... }` block inside a module.
fn parse_test_case(input: ParseStream) -> syn::Result<TestCase> {
consume_ident_or_keyword(input)?; // "test"
let name: Ident = input.parse()?;
let content;
braced!(content in input);
let mut case = TestCase {
name,
actions: Vec::new(),
stdout: None,
stderr_contains: None,
exit_code: None,
query: None,
match_labels: None,
cursor: None,
offset: None,
selected: None,
cancelled: false,
};
while !content.is_empty() {
let field = parse_ident_or_keyword(&content)?;
// Consume the ident we just peeked.
consume_ident_or_keyword(&content)?;
match field.as_str() {
"actions" => {
content.parse::<Token![:]>()?;
case.actions = parse_action_list(&content)?;
}
"stdout" => {
content.parse::<Token![:]>()?;
let val: LitStr = content.parse()?;
case.stdout = Some(val.value());
}
"stderr" => {
// stderr contains: "text"
let kw = parse_ident_or_keyword(&content)?;
consume_ident_or_keyword(&content)?;
if kw != "contains" {
return Err(syn::Error::new(
content.span(),
"expected 'contains' after 'stderr'",
));
}
content.parse::<Token![:]>()?;
let val: LitStr = content.parse()?;
case.stderr_contains = Some(val.value());
}
"exit" => {
content.parse::<Token![:]>()?;
let val: LitInt = content.parse()?;
case.exit_code = Some(val.base10_parse()?);
}
"query" => {
content.parse::<Token![:]>()?;
let val: LitStr = content.parse()?;
case.query = Some(val.value());
}
"matches" => {
content.parse::<Token![:]>()?;
case.match_labels = Some(parse_string_list(&content)?);
}
"cursor" => {
content.parse::<Token![:]>()?;
let val: LitInt = content.parse()?;
case.cursor = Some(val.base10_parse()?);
}
"offset" => {
content.parse::<Token![:]>()?;
let val: LitInt = content.parse()?;
case.offset = Some(val.base10_parse()?);
}
"selected" => {
content.parse::<Token![:]>()?;
let val: LitStr = content.parse()?;
case.selected = Some(val.value());
}
"cancelled" => {
// Just the keyword presence means true. Optionally parse `: true`.
if content.peek(Token![:]) {
content.parse::<Token![:]>()?;
// Accept `true` or just skip
if content.peek(Ident) {
consume_ident_or_keyword(&content)?;
}
}
case.cancelled = true;
}
_ => {
return Err(syn::Error::new(
content.span(),
format!("unknown test field: '{field}'"),
));
}
}
}
Ok(case)
}
// ---------------------------------------------------------------------------
// Action parsing
// ---------------------------------------------------------------------------
/// Parse `[action1, action2, ...]` inside a test case's
/// `actions:` field.
fn parse_action_list(input: ParseStream) -> syn::Result<Vec<ActionExpr>> {
let content;
bracketed!(content in input);
let mut actions = Vec::new();
while !content.is_empty() {
actions.push(parse_action_expr(&content)?);
if content.peek(Token![,]) {
content.parse::<Token![,]>()?;
}
}
Ok(actions)
}
/// Parse a single action expression: `confirm`, `filter "text"`,
/// `raw "line"`, or `add-items ["a", "b"]`.
fn parse_action_expr(input: ParseStream) -> syn::Result<ActionExpr> {
let name = parse_hyphenated_name(input)?;
match name.as_str() {
"filter" => {
let val: LitStr = input.parse()?;
Ok(ActionExpr::Filter(val.value()))
}
"raw" => {
let val: LitStr = input.parse()?;
Ok(ActionExpr::Raw(val.value()))
}
"add-items" => {
let items = parse_string_list(input)?;
Ok(ActionExpr::AddItems(items))
}
_ => Ok(ActionExpr::Simple(name)),
}
}
// ---------------------------------------------------------------------------
// Helpers
// ---------------------------------------------------------------------------
/// Parse the test module kind keyword: `headless`, `filter`,
/// `nav`, or `menu`.
fn parse_kind(input: ParseStream) -> syn::Result<TestKind> {
let ident: Ident = input.parse()?;
match ident.to_string().as_str() {
"headless" => Ok(TestKind::Headless),
"filter" => Ok(TestKind::Filter),
"nav" => Ok(TestKind::Nav),
"menu" => Ok(TestKind::Menu),
other => Err(syn::Error::new(
ident.span(),
format!("unknown test kind '{other}', expected headless, filter, nav, or menu"),
)),
}
}
/// Parse a potentially hyphenated name like "move-down" or "move-to-top".
/// Handles the `move` keyword specially since it's reserved in Rust.
fn parse_hyphenated_name(input: ParseStream) -> syn::Result<String> {
let mut name = String::new();
// First segment: might be the `move` keyword or a regular ident.
if input.peek(Token![move]) {
input.parse::<Token![move]>()?;
name.push_str("move");
} else {
let ident: Ident = input.parse()?;
name.push_str(&ident.to_string());
}
// Consume hyphenated continuations: `-ident`
// Be careful not to consume `-` that's actually a negative number.
while input.peek(Token![-]) && !input.peek2(LitInt) {
input.parse::<Token![-]>()?;
name.push('-');
if input.peek(Token![move]) {
input.parse::<Token![move]>()?;
name.push_str("move");
} else {
let next: Ident = input.parse()?;
name.push_str(&next.to_string());
}
}
Ok(name)
}
/// Parse `["a", "b", "c"]`.
fn parse_string_list(input: ParseStream) -> syn::Result<Vec<String>> {
let content;
bracketed!(content in input);
let mut items = Vec::new();
while !content.is_empty() {
let val: LitStr = content.parse()?;
items.push(val.value());
if content.peek(Token![,]) {
content.parse::<Token![,]>()?;
}
}
Ok(items)
}
/// Parse `{ height: N, count: N }`.
fn parse_viewport_def(input: ParseStream) -> syn::Result<(usize, usize)> {
let content;
braced!(content in input);
let mut height: Option<usize> = None;
let mut count: Option<usize> = None;
while !content.is_empty() {
let key: Ident = content.parse()?;
content.parse::<Token![:]>()?;
let val: LitInt = content.parse()?;
let n: usize = val.base10_parse()?;
match key.to_string().as_str() {
"height" => height = Some(n),
"count" => count = Some(n),
other => {
return Err(syn::Error::new(
key.span(),
format!("unknown viewport field '{other}', expected height or count"),
));
}
}
if content.peek(Token![,]) {
content.parse::<Token![,]>()?;
}
}
let h =
height.ok_or_else(|| syn::Error::new(Span::call_site(), "viewport missing 'height'"))?;
let c = count.ok_or_else(|| syn::Error::new(Span::call_site(), "viewport missing 'count'"))?;
Ok((h, c))
}
/// Peek at the next ident-like token without consuming it.
/// Handles Rust keywords that might appear as DSL field names.
fn parse_ident_or_keyword(input: ParseStream) -> syn::Result<String> {
if input.peek(Token![move]) {
Ok("move".to_string())
} else if input.peek(Token![match]) {
Ok("match".to_string())
} else if input.peek(Ident) {
let fork = input.fork();
let ident: Ident = fork.parse()?;
Ok(ident.to_string())
} else {
Err(input.error("expected identifier"))
}
}
/// Consume an ident-like token (including keywords used as DSL fields).
fn consume_ident_or_keyword(input: ParseStream) -> syn::Result<()> {
if input.peek(Token![move]) {
input.parse::<Token![move]>()?;
} else if input.peek(Token![match]) {
input.parse::<Token![match]>()?;
} else {
input.parse::<Ident>()?;
}
Ok(())
}
/// Eat an optional semicolon.
fn eat_semi(input: ParseStream) {
if input.peek(Token![;]) {
let _ = input.parse::<Token![;]>();
}
}