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big_code_analysis/
ops.rs

1// Per-language metric and AST modules deliberately consume the macro-
2// generated tree-sitter token enums via `use crate::*` and `use Foo::*`
3// inside match expressions — explicit imports would list dozens of
4// variants per arm and obscure the per-language token sets that are the
5// point of these files. Allowed at the module level rather than per
6// function so the per-language impl blocks stay readable.
7#![allow(clippy::wildcard_imports, clippy::enum_glob_use)]
8
9use std::borrow::Cow;
10
11use crate::checker::Checker;
12use crate::error::MetricsError;
13use crate::getter::Getter;
14use crate::node::{Ancestors, Node};
15use crate::spaces::{SpaceKind, line_span, push_children};
16
17use crate::halstead::{Halstead, HalsteadMaps};
18
19use crate::MetricSuite;
20
21/// All operands and operators of a space.
22#[derive(Debug, Clone)]
23pub struct Ops {
24    /// The name of a function space.
25    ///
26    /// For the top-level (file-level) `Ops` the value is whatever
27    /// `Source::name` the caller supplied to the [`crate::Ast::ops`]
28    /// seam — `Some` or `None`.
29    ///
30    /// For nested spaces, `None` means an error occurred in parsing the
31    /// name of the function space from the AST.
32    pub name: Option<String>,
33    /// `true` when [`Ops::name`] was produced by lossy conversion (the
34    /// original path contained non-UTF-8 bytes and was rendered using
35    /// U+FFFD replacement characters). The explicit-name
36    /// [`crate::Ast::ops`] seam never sets it, since a caller-supplied
37    /// `String` name is UTF-8 by construction, so it is always `false`
38    /// in current code paths. Retained as a wire field for forward
39    /// compatibility; skipped from JSON output when `false` so existing
40    /// schemas keep their shape.
41    pub name_was_lossy: bool,
42    /// The first line of a function space.
43    pub start_line: usize,
44    /// The last line of a function space.
45    pub end_line: usize,
46    /// The space kind.
47    pub kind: SpaceKind,
48    /// All subspaces contained in a function space.
49    pub spaces: Vec<Ops>,
50    /// The **distinct** operands of a space — the deduplicated Halstead
51    /// operand vocabulary (`n2`), one entry per unique operand, not every
52    /// occurrence. Sorted in byte-lexicographic order, so the same input
53    /// always yields the same sequence (#1091).
54    pub operands: Vec<String>,
55    /// The **distinct** operators of a space — the deduplicated Halstead
56    /// operator vocabulary (`n1`), one entry per unique operator, not
57    /// every occurrence. Sorted in byte-lexicographic order, so the same
58    /// input always yields the same sequence (#1091).
59    pub operators: Vec<String>,
60}
61
62// Space nesting is caller-controlled, so the compiler-generated `Drop`
63// glue would recurse once per level and abort the process on a deep tree
64// (#1056). See [`crate::recursion`].
65crate::recursion::impl_iterative_drop!(Ops, spaces);
66
67impl Ops {
68    /// Project this tree into its [`crate::wire::Ops`] form — the
69    /// plain, `Deserialize`-capable record that defines the serialized
70    /// shape.
71    #[must_use]
72    pub fn to_wire(&self) -> crate::wire::Ops {
73        crate::wire::Ops::from(self)
74    }
75
76    fn new<'a, T: Getter>(
77        node: &Node<'a>,
78        code: &[u8],
79        ancestors: Ancestors<'a, '_>,
80        kind: SpaceKind,
81    ) -> Self {
82        let (start_position, end_position) = line_span(node, kind);
83        // The top-level Unit's name is overwritten by `ops_inner` with the
84        // caller-supplied name before returning, so computing it here is
85        // wasted work. Non-top-level Unit spaces have no resolvable name, so
86        // leaving `None` matches the documented "could not be resolved"
87        // semantics rather than inventing the `<anonymous>` placeholder the
88        // default getter returns. Other kinds keep the AST-derived name.
89        // Mirrors the `SpaceKind::Unit` handling in `FuncSpace::new`.
90        let name = (kind != SpaceKind::Unit)
91            .then(|| T::get_func_space_name(node, code, ancestors).map(str::to_owned))
92            .flatten();
93        Self {
94            name,
95            name_was_lossy: false,
96            spaces: Vec::new(),
97            kind,
98            start_line: start_position,
99            end_line: end_position,
100            operators: Vec::new(),
101            operands: Vec::new(),
102        }
103    }
104}
105
106#[derive(Debug, Clone)]
107struct State<'a> {
108    ops: Ops,
109    halstead_maps: HalsteadMaps<'a>,
110}
111
112/// Pushes a synthetic `Unit` root onto the state stack when the grammar
113/// hands us a non-`Unit` root.
114///
115/// Mirrors [`crate::spaces::push_synthetic_unit_root`] on the metrics
116/// seam: some grammars (e.g. tree-sitter-lua / tree-sitter-mozcpp on
117/// unparseable input) return an `ERROR` root that is not classified as a
118/// function space, so without this push the walk would never open a
119/// frame and `ops_inner` would return [`MetricsError::EmptyRoot`] for an
120/// input where `metrics()` succeeds (issue #789). A `Unit` root needs no
121/// wrapper, so nothing is pushed in that case.
122fn push_synthetic_unit_root<T: MetricSuite>(
123    state_stack: &mut Vec<State>,
124    node: &Node,
125    code: &[u8],
126) {
127    // `Ancestors::unknown()`: `node` is the tree root here, so it has
128    // no ancestors to hand over either way.
129    if T::Getter::get_space_kind_with_code(node, code, Ancestors::unknown()) != SpaceKind::Unit {
130        state_stack.push(State {
131            ops: Ops::new::<T::Getter>(node, code, Ancestors::unknown(), SpaceKind::Unit),
132            halstead_maps: HalsteadMaps::new(),
133        });
134    }
135}
136
137// Space-kind classifications `ops_inner` has performed on this thread.
138//
139// The classification only ever reaches `Ops::new`, so running it on a
140// node that opens no space is work thrown away — and nothing about the
141// walk's *output* can tell the two apart. The counter is the
142// observable: it reads one per space after the lookup was moved inside
143// the `func_space` branch, and one per *node* before, which is what
144// makes hoisting it back out a test failure rather than a silent
145// regression (#1110).
146crate::observation::counter!(space_kind_lookups);
147
148/// Classifies a node that is about to open a function space.
149///
150/// Classification happens after the decision that a space opens, the
151/// same way [`crate::spaces::compute`]'s `open_func_space` does it
152/// (#522), and through the same source-aware classifier, so a space
153/// both seams open carries the same [`SpaceKind`] in either walk.
154/// The `_with_code` variant is what lets Elixir's macro-shaped
155/// `defmodule` / `def` declarations — plain `Call` nodes distinguished
156/// only by their target identifier text — come back as `Class` /
157/// `Function` rather than `Unknown` (#275, #1130).
158///
159/// The lookup is a per-language `match` on the node's kind for most
160/// grammars, but C#'s reaches a child scan for a bodied indexer or
161/// property and Elixir's reads the `Call` target text and scans the
162/// ancestor chain for an enclosing `quote` block, so it is not free on
163/// every node either.
164fn classify_space_kind<'a, T: MetricSuite>(
165    node: &Node<'a>,
166    code: &[u8],
167    ancestors: Ancestors<'a, '_>,
168) -> SpaceKind {
169    space_kind_lookups::record();
170    T::Getter::get_space_kind_with_code(node, code, ancestors)
171}
172
173/// Render a space's vocabulary: byte-lexicographically ordered, one
174/// owned `String` per distinct entry.
175///
176/// # Order
177///
178/// `HashMap`'s hasher is randomly seeded per instance, so key order
179/// differs between two runs — and even between two parses in one
180/// process. Without a canonical order the same input renders and
181/// serializes differently every time, which makes `bca ops` output
182/// undiffable and unusable as a cache key (#1091).
183///
184/// Byte-lexicographic, not first-appearance, order: `finalize` merges
185/// a child space's maps into its parent, so an insertion-ordered map
186/// would give the parent "what it saw directly, then whatever each
187/// child contributed" — a walk artifact that shifts when nesting
188/// changes. Sorting is also stable across platforms and hasher
189/// versions, which insertion order via a different map type is not.
190///
191/// # Why the sort runs before the `String`s exist
192///
193/// Every ancestor of a space re-renders that space's whole vocabulary:
194/// `finalize` merges each child's Halstead maps into its parent, so a
195/// parent's key set is a superset of every descendant's and an entry
196/// nested `D` spaces deep is rendered `D + 1` times. Sorting the
197/// borrowed keys first makes each swap a fat pointer rather than a
198/// 24-byte `String`, and — because the `String`s are then allocated in
199/// output order — it hands every later pass over them (the wire
200/// projection, serialization, the `dump_ops` tree) a heap laid out in
201/// the order it reads. Issue #1110 measured both effects.
202///
203/// # Non-UTF-8 keys
204///
205/// Tree-sitter sources are expected to be valid UTF-8; non-UTF-8 bytes
206/// are replaced with the Unicode replacement character to keep the entry
207/// visible (rather than silently dropping it or using a sentinel string
208/// that could collide with a real identifier). That rendering is not
209/// order-preserving — `b"\xffA"` sorts after `"\u{fffd}B"` by raw bytes
210/// and before it once both are rendered — so a vocabulary that actually
211/// lost bytes is re-sorted on the rendered text, which is the order the
212/// pre-#1110 render-then-sort code produced. Valid UTF-8, which is every
213/// key in practice, takes the single sort.
214fn sorted_vocabulary(mut keys: Vec<&[u8]>) -> Vec<String> {
215    keys.sort_unstable();
216    let mut lossy = false;
217    let mut rendered: Vec<String> = keys
218        .into_iter()
219        .map(|key| match String::from_utf8_lossy(key) {
220            Cow::Borrowed(text) => text.to_owned(),
221            Cow::Owned(text) => {
222                lossy = true;
223                text
224            }
225        })
226        .collect();
227    if lossy {
228        rendered.sort_unstable();
229    }
230    rendered
231}
232
233fn compute_operators_and_operands<T: MetricSuite>(state: &mut State) {
234    let maps = &state.halstead_maps;
235
236    // Primitive-type operators live in a second map (keyed by text rather
237    // than by token id), so the operator vocabulary is the concatenation
238    // of both key sets.
239    let operators = maps
240        .operators
241        .keys()
242        .map(|k| T::Getter::get_operator_id_as_str(*k).as_bytes())
243        .chain(maps.primitive_operators.keys().copied())
244        .collect();
245
246    state.ops.operators = sorted_vocabulary(operators);
247    state.ops.operands = sorted_vocabulary(maps.operands.keys().copied().collect());
248}
249
250/// Close up to `diff_level` open spaces, folding each into its parent.
251///
252/// Only the states this pops get their vocabularies computed. The
253/// bottom state is never popped here, so the root's vocabulary is built
254/// once by [`ops_inner`] after the final drain — computing it on every
255/// call would rebuild (and, since #1091, re-sort) the whole file's
256/// vocabulary once per level-drop in the walk, and every result but the
257/// last would be overwritten.
258fn finalize<T: MetricSuite>(state_stack: &mut Vec<State>, diff_level: usize) {
259    for _ in 0..diff_level {
260        if state_stack.len() < 2 {
261            break;
262        }
263        let mut state = state_stack
264            .pop()
265            .expect("state_stack verified to have len >= 2");
266        let last_state = state_stack
267            .last_mut()
268            .expect("state_stack verified to have len >= 1 after pop");
269
270        // Populate the child's ops from its HalsteadMaps before
271        // recording it as a sub-space of the parent.
272        compute_operators_and_operands::<T>(&mut state);
273
274        // Merge child's Halstead maps into parent and record child space.
275        last_state.halstead_maps.merge(&state.halstead_maps);
276        last_state.ops.spaces.push(state.ops);
277    }
278}
279
280/// Context the ops walk carries down the tree alongside each node.
281///
282/// A named pair rather than a `(usize, usize)`: the two counts advance
283/// on different events and swapping them is silent — `level` only moves
284/// at space boundaries while `depth` counts every AST step. Mirrors
285/// [`crate::spaces::compute`]'s `Walk`, minus the comment flag this walk
286/// has no use for.
287#[derive(Clone, Copy)]
288struct Walk {
289    /// Nesting level, used to close op-spaces on the way back up.
290    level: usize,
291    /// AST depth — the number of ancestors this node has, so the root
292    /// sits at `0`. Indexes the ancestor chain the walk maintains.
293    depth: usize,
294}
295
296/// Explicit-name core of the operator/operand walk backing the
297/// [`crate::Ast::ops`] `Source`-based seam. The top-level [`Ops::name`]
298/// is whatever the caller passes in `name`; `name_was_lossy` is left at
299/// its `false` default because an explicit `String` name is never lossy.
300/// Mirrors [`crate::spaces::metrics_inner`].
301pub(crate) fn ops_inner<T: MetricSuite>(
302    parser: &T,
303    name: Option<String>,
304) -> Result<Ops, MetricsError> {
305    let code = parser.code();
306    let node = parser.root();
307    let mut cursor = node.cursor();
308    let mut stack = Vec::new();
309    // Ancestor chain of the node currently being visited, root first,
310    // maintained by the same truncate/push rule as
311    // `spaces::compute::metrics_inner` (#1084).
312    let mut chain: Vec<Node<'_>> = Vec::new();
313    let mut state_stack: Vec<State> = Vec::new();
314    let mut last_level = 0;
315
316    // Mirror `metrics_inner`: wrap a non-`Unit` (e.g. `ERROR`) root in a
317    // synthetic `Unit` frame so the walk always has a frame to populate.
318    // Without this, an `ERROR`-root parse drains the state stack and
319    // `ops_inner` returns `EmptyRoot` for inputs where `metrics()`
320    // succeeds (issue #789).
321    push_synthetic_unit_root::<T>(&mut state_stack, &node, code);
322
323    stack.push((node, Walk { level: 0, depth: 0 }));
324
325    while let Some((node, Walk { level, depth })) = stack.pop() {
326        chain.truncate(depth);
327
328        if level < last_level {
329            finalize::<T>(&mut state_stack, last_level - level);
330            last_level = level;
331        }
332
333        let ancestors = Ancestors::checked(&chain, &node);
334
335        // Same predicate `spaces::compute::metrics_inner` opens on, so
336        // the two walks agree on which nodes become spaces. The
337        // byte-less `is_func || is_func_space` this replaced could not
338        // see Elixir's macro-shaped declarations, which are `Call`
339        // nodes identified by their target text, so `bca ops` opened no
340        // space for a `defmodule` / `def` / `defp` / `defmacro` — only
341        // for `Source` and an explicit `fn … -> … end` (#1130).
342        let func_space = T::Checker::promotes_to_func_space_with_code(&node, code, ancestors);
343
344        let new_level = if func_space {
345            let kind = classify_space_kind::<T>(&node, code, ancestors);
346            let state = State {
347                ops: Ops::new::<T::Getter>(&node, code, ancestors, kind),
348                halstead_maps: HalsteadMaps::new(),
349            };
350            state_stack.push(state);
351            last_level = level + 1;
352            last_level
353        } else {
354            level
355        };
356
357        if let Some(state) = state_stack.last_mut() {
358            T::Halstead::compute(&node, code, ancestors, &mut state.halstead_maps);
359        }
360
361        chain.push(node);
362
363        // Shared with `metrics_inner` (issue #969): `push_children` is
364        // State-independent — it only moves the cursor over child nodes —
365        // so unlike the local `finalize` / `push_synthetic_unit_root`
366        // mirrors (which differ by `State` payload) it is reused directly
367        // rather than duplicated. The source-order-then-reverse ordering
368        // it encapsulates is load-bearing for suppression attribution.
369        // The returned child slice is only useful to `metrics_inner`,
370        // which seeds their cognitive nesting; `ops` just walks them.
371        push_children(
372            &mut cursor,
373            &node,
374            Walk {
375                level: new_level,
376                depth: depth + 1,
377            },
378            &mut stack,
379        );
380    }
381
382    finalize::<T>(&mut state_stack, usize::MAX);
383
384    // Reserved error path: `MetricsError::EmptyRoot` is unreachable
385    // today because the synthetic Unit push above (and every supported
386    // language's root being recognised as a `func_space`) keeps the
387    // state stack non-empty for every input, including ERROR-root,
388    // empty, whitespace-only, and comment-only sources — matching
389    // `metrics_inner`. The `ok_or` is retained so a future walker change
390    // that legitimately drains the stack surfaces a distinct error
391    // variant rather than a bare `None`. See `MetricsError::EmptyRoot`
392    // for the matching variant doc.
393    let mut state = state_stack.pop().ok_or(MetricsError::EmptyRoot)?;
394    // The root is the one state `finalize` never pops, so its vocabulary
395    // is built here — once, from the fully-merged maps.
396    compute_operators_and_operands::<T>(&mut state);
397    state.ops.name = name;
398    Ok(state.ops)
399}
400
401#[cfg(test)]
402#[allow(
403    clippy::float_cmp,
404    clippy::cast_precision_loss,
405    clippy::cast_possible_truncation,
406    clippy::cast_sign_loss,
407    clippy::similar_names,
408    clippy::doc_markdown,
409    clippy::needless_raw_string_hashes,
410    clippy::too_many_lines
411)]
412mod tests {
413    use super::Ops;
414    use crate::{Ast, LANG, Source};
415
416    #[cfg(any(
417        feature = "cpp",
418        feature = "java",
419        feature = "javascript",
420        feature = "mozjs",
421        feature = "perl",
422        feature = "python",
423        feature = "rust",
424        feature = "typescript",
425    ))]
426    #[inline]
427    fn check_ops(
428        lang: LANG,
429        source: &str,
430        file: &str,
431        correct_operators: &mut [&str],
432        correct_operands: &mut [&str],
433    ) {
434        let mut trimmed_bytes = source.trim_end().trim_matches('\n').as_bytes().to_vec();
435        trimmed_bytes.push(b'\n');
436        let ops = Ast::parse(Source::new(lang, &trimmed_bytes).with_name(Some(file.to_owned())))
437            .expect("language feature enabled")
438            .ops()
439            .expect("ops walk must yield a top-level Ops");
440
441        let operators_str: Vec<&str> = ops.operators.iter().map(AsRef::as_ref).collect();
442        let operands_str: Vec<&str> = ops.operands.iter().map(AsRef::as_ref).collect();
443
444        // Only the *expectations* are sorted here: `Ops` is documented to
445        // come back byte-lexicographically ordered (#1091), so comparing
446        // against a sorted expectation without re-sorting the actual value
447        // makes every `check_ops` caller an ordering regression test for
448        // its language.
449        correct_operators.sort_unstable();
450        assert_eq!(&operators_str[..], correct_operators);
451
452        correct_operands.sort_unstable();
453        assert_eq!(&operands_str[..], correct_operands);
454    }
455
456    #[cfg(feature = "python")]
457    #[test]
458    fn python_ops() {
459        check_ops(
460            LANG::Python,
461            "if True:
462                 a = 1 + 2",
463            "foo.py",
464            &mut ["if", "=", "+"],
465            &mut ["True", "a", "1", "2"],
466        );
467    }
468
469    #[cfg(feature = "perl")]
470    #[test]
471    fn perl_pattern_operations_render_as_source_spellings() {
472        // #1314 classifies `s///` and `tr///` as Halstead operators.
473        // They are *named* nodes rather than punctuation tokens, so the
474        // `get_operator!` macro's fallback would render each kind's own
475        // name — `substitution_pattern_s`, `transliteration_tr_or_y` —
476        // into `bca ops`, which reads as a bug rather than as Perl.
477        // `PerlCode::get_operator_id_as_str` is hand-written to map
478        // them, and this is what pins that mapping: the counts alone
479        // cannot see it.
480        //
481        // `y///` is a synonym of `tr///` and shares one kind, so the
482        // two source spellings collapse to a single `tr///` entry —
483        // asserted here by the *absence* of a `y///` row in an
484        // exhaustive expectation, not by a negative assertion.
485        //
486        // The trailing `/pat/` keeps a pattern *value* in the fixture,
487        // so the test also shows the split: the operation spellings are
488        // operators while the value is an operand.
489        check_ops(
490            LANG::Perl,
491            "$s =~ s/a/b/;\n$s =~ tr/c/d/;\n$s =~ y/e/f/;\n$t = /pat/;",
492            "foo.pl",
493            &mut ["$", ";", "=", "=~", "s///", "tr///"],
494            &mut ["$s", "$t", "/pat/"],
495        );
496    }
497
498    #[cfg(feature = "python")]
499    #[test]
500    fn python_function_ops() {
501        check_ops(
502            LANG::Python,
503            "def foo():
504                 def bar():
505                     def toto():
506                        a = 1 + 1
507                     b = 2 + a
508                 c = 3 + 3",
509            "foo.py",
510            &mut ["def", "=", "+"],
511            &mut ["foo", "bar", "toto", "a", "b", "c", "1", "2", "3"],
512        );
513    }
514
515    #[cfg(feature = "cpp")]
516    #[test]
517    fn cpp_ops() {
518        check_ops(
519            LANG::Cpp,
520            "int a, b, c;
521             float avg;
522             avg = (a + b + c) / 3;",
523            "foo.c",
524            &mut ["int", "float", "()", "=", "+", "/", ",", ";"],
525            &mut ["a", "b", "c", "avg", "3"],
526        );
527    }
528
529    #[cfg(feature = "cpp")]
530    #[test]
531    fn cpp_function_ops() {
532        check_ops(
533            LANG::Cpp,
534            "main()
535            {
536              int a, b, c, avg;
537              scanf(\"%d %d %d\", &a, &b, &c);
538              avg = (a + b + c) / 3;
539              printf(\"avg = %d\", avg);
540            }",
541            "foo.c",
542            &mut ["()", "{}", "int", "&", "=", "+", "/", ",", ";"],
543            &mut [
544                "main",
545                "a",
546                "b",
547                "c",
548                "avg",
549                "scanf",
550                "\"%d %d %d\"",
551                "3",
552                "printf",
553                "\"avg = %d\"",
554            ],
555        );
556    }
557
558    #[cfg(feature = "rust")]
559    #[test]
560    fn rust_ops() {
561        check_ops(
562            LANG::Rust,
563            "let: usize a = 5; let b: f32 = 7.0; let c: i32 = 3;",
564            "foo.rs",
565            &mut ["let", "usize", "=", ";", "f32", "i32"],
566            &mut ["a", "b", "c", "5", "7.0", "3"],
567        );
568    }
569
570    #[cfg(feature = "rust")]
571    #[test]
572    fn rust_function_ops() {
573        check_ops(
574            LANG::Rust,
575            "fn main() {
576              let a = 5; let b = 5; let c = 5;
577              let avg = (a + b + c) / 3;
578              println!(\"{}\", avg);
579            }",
580            "foo.rs",
581            &mut ["fn", "()", "{}", "let", "=", "+", "/", ";", "!", ","],
582            &mut ["main", "a", "b", "c", "avg", "5", "3", "println", "\"{}\""],
583        );
584    }
585
586    #[cfg(feature = "javascript")]
587    #[test]
588    fn javascript_ops() {
589        check_ops(
590            LANG::Javascript,
591            "var a, b, c, avg;
592             let x = 1;
593             a = 5; b = 5; c = 5;
594             avg = (a + b + c) / 3;
595             console.log(\"{}\", avg);",
596            "foo.js",
597            &mut ["()", "var", "let", "=", "+", "/", ",", ".", ";"],
598            &mut [
599                "a", "b", "c", "avg", "x", "1", "3", "5", "console", "log", "\"{}\"",
600            ],
601        );
602    }
603
604    #[cfg(feature = "javascript")]
605    #[test]
606    fn javascript_function_ops() {
607        check_ops(
608            LANG::Javascript,
609            "function main() {
610              var a, b, c, avg;
611              let x = 1;
612              a = 5; b = 5; c = 5;
613              avg = (a + b + c) / 3;
614              console.log(\"{}\", avg);
615            }",
616            "foo.js",
617            &mut [
618                "function", "()", "{}", "var", "let", "=", "+", "/", ",", ".", ";",
619            ],
620            &mut [
621                "main", "a", "b", "c", "avg", "x", "1", "3", "5", "console", "log", "\"{}\"",
622            ],
623        );
624    }
625
626    #[cfg(feature = "mozjs")]
627    #[test]
628    fn mozjs_ops() {
629        check_ops(
630            LANG::Mozjs,
631            "var a, b, c, avg;
632             let x = 1;
633             a = 5; b = 5; c = 5;
634             avg = (a + b + c) / 3;
635             console.log(\"{}\", avg);",
636            "foo.js",
637            &mut ["()", "var", "let", "=", "+", "/", ",", ".", ";"],
638            &mut [
639                "a", "b", "c", "avg", "x", "1", "3", "5", "console", "log", "\"{}\"",
640            ],
641        );
642    }
643
644    #[cfg(feature = "mozjs")]
645    #[test]
646    fn mozjs_function_ops() {
647        check_ops(
648            LANG::Mozjs,
649            "function main() {
650              var a, b, c, avg;
651              let x = 1;
652              a = 5; b = 5; c = 5;
653              avg = (a + b + c) / 3;
654              console.log(\"{}\", avg);
655            }",
656            "foo.js",
657            &mut [
658                "function", "()", "{}", "var", "let", "=", "+", "/", ",", ".", ";",
659            ],
660            &mut [
661                "main", "a", "b", "c", "avg", "x", "1", "3", "5", "console", "log", "\"{}\"",
662            ],
663        );
664    }
665
666    #[cfg(feature = "typescript")]
667    #[test]
668    fn typescript_ops() {
669        // Issue #1261: the `: string` annotation counts exactly once,
670        // as the text-keyed `string` operator (PredefinedType wrapper)
671        // — symmetric with `: number` / `: boolean`. Under #313 its
672        // `String2` child also emitted a `"string"` operand, so one
673        // source token tallied twice.
674        check_ops(
675            LANG::Typescript,
676            "var a, b, c, avg;
677             let age: number = 32;
678             let name: string = \"John\"; let isUpdated: boolean = true;
679             a = 5; b = 5; c = 5;
680             avg = (a + b + c) / 3;
681             console.log(\"{}\", avg);",
682            "foo.ts",
683            &mut [
684                "()", "var", "let", "string", "number", "boolean", ":", "=", "+", "/", ",", ".",
685                ";",
686            ],
687            &mut [
688                "a",
689                "b",
690                "c",
691                "avg",
692                "age",
693                "name",
694                "isUpdated",
695                "32",
696                "\"John\"",
697                "true",
698                "3",
699                "5",
700                "console",
701                "log",
702                "\"{}\"",
703            ],
704        );
705    }
706
707    #[cfg(feature = "typescript")]
708    #[test]
709    fn typescript_function_ops() {
710        // Issue #1261: see `typescript_ops` — the `string` type keyword
711        // contributes only the primitive-typed operator, never a
712        // `"string"` operand.
713        check_ops(
714            LANG::Typescript,
715            "function main() {
716              var a, b, c, avg;
717              let age: number = 32;
718              let name: string = \"John\"; let isUpdated: boolean = true;
719              a = 5; b = 5; c = 5;
720              avg = (a + b + c) / 3;
721              console.log(\"{}\", avg);
722            }",
723            "foo.ts",
724            &mut [
725                "function", "()", "{}", "var", "let", "string", "number", "boolean", ":", "=", "+",
726                "/", ",", ".", ";",
727            ],
728            &mut [
729                "main",
730                "a",
731                "b",
732                "c",
733                "avg",
734                "age",
735                "name",
736                "isUpdated",
737                "32",
738                "\"John\"",
739                "true",
740                "3",
741                "5",
742                "console",
743                "log",
744                "\"{}\"",
745            ],
746        );
747    }
748
749    #[cfg(feature = "typescript")]
750    #[test]
751    fn tsx_ops() {
752        // Issue #1261: TSX exposes the `: string` type-keyword child as
753        // `String3` (vs. TS's `String2`); like TS, the keyword counts
754        // only as the `string` operator, never as an operand.
755        check_ops(
756            LANG::Tsx,
757            "var a, b, c, avg;
758             let age: number = 32;
759             let name: string = \"John\"; let isUpdated: boolean = true;
760             a = 5; b = 5; c = 5;
761             avg = (a + b + c) / 3;
762             console.log(\"{}\", avg);",
763            "foo.ts",
764            &mut [
765                "()", "var", "let", "string", "number", "boolean", ":", "=", "+", "/", ",", ".",
766                ";",
767            ],
768            &mut [
769                "a",
770                "b",
771                "c",
772                "avg",
773                "age",
774                "name",
775                "isUpdated",
776                "32",
777                "\"John\"",
778                "true",
779                "3",
780                "5",
781                "console",
782                "log",
783                "\"{}\"",
784            ],
785        );
786    }
787
788    #[cfg(feature = "typescript")]
789    #[test]
790    fn tsx_function_ops() {
791        // Issue #1261: see `tsx_ops` — TSX::String3 (type-keyword
792        // `string`) is an operator only, never an operand.
793        check_ops(
794            LANG::Tsx,
795            "function main() {
796              var a, b, c, avg;
797              let age: number = 32;
798              let name: string = \"John\"; let isUpdated: boolean = true;
799              a = 5; b = 5; c = 5;
800              avg = (a + b + c) / 3;
801              console.log(\"{}\", avg);
802            }",
803            "foo.ts",
804            &mut [
805                "function", "()", "{}", "var", "let", "string", "number", "boolean", ":", "=", "+",
806                "/", ",", ".", ";",
807            ],
808            &mut [
809                "main",
810                "a",
811                "b",
812                "c",
813                "avg",
814                "age",
815                "name",
816                "isUpdated",
817                "32",
818                "\"John\"",
819                "true",
820                "3",
821                "5",
822                "console",
823                "log",
824                "\"{}\"",
825            ],
826        );
827    }
828
829    // Issue #453: a `void` return type (a `predefined_type` wrapper over a
830    // `void` token) and an expression `void` (`void 0`) must collapse to a
831    // single distinct `"void"` operator. `check_ops` asserts the exact
832    // operator list, so a duplicate `"void"` — the pre-fix symptom, where
833    // the wrapper keyed `primitive_operators["void"]` and the inner token
834    // keyed `operators[Void]` — trips the assertion. This pins the lesson-4
835    // `n1 == dedupe(ops.operators)` invariant for the two `void` forms in
836    // one file.
837    #[cfg(feature = "typescript")]
838    #[test]
839    fn typescript_void_return_and_expression_single_operator_453() {
840        check_ops(
841            LANG::Typescript,
842            "function f(): void { return void 0; }",
843            "foo.ts",
844            &mut ["function", "()", "{}", ":", "void", "return", ";"],
845            &mut ["f", "0"],
846        );
847    }
848
849    #[cfg(feature = "typescript")]
850    #[test]
851    fn tsx_void_return_and_expression_single_operator_453() {
852        check_ops(
853            LANG::Tsx,
854            "function f(): void { return void 0; }",
855            "foo.tsx",
856            &mut ["function", "()", "{}", ":", "void", "return", ";"],
857            &mut ["f", "0"],
858        );
859    }
860
861    #[cfg(feature = "java")]
862    #[test]
863    fn java_ops() {
864        check_ops(
865            LANG::Java,
866            "public class Main {
867                public static void main(string args[]) {
868                      int a, b, c, avg;
869                      a = 5; b = 5; c = 5;
870                      avg = (a + b + c) / 3;
871                      MessageFormat.format(\"{0}\", avg);
872                    }
873                }",
874            "foo.java",
875            &mut [
876                "{}", "void", "()", "[]", ",", ".", ";", "int", "=", "+", "/",
877            ],
878            &mut [
879                "Main",
880                "main",
881                "args",
882                "a",
883                "b",
884                "c",
885                "avg",
886                "5",
887                "3",
888                "MessageFormat",
889                "format",
890                "\"{0}\"",
891            ],
892        );
893    }
894
895    #[cfg(feature = "java")]
896    #[test]
897    fn java_primitive_ops() {
898        check_ops(
899            LANG::Java,
900            "public class Prims {
901                byte a = 1;
902                short b = 2;
903                int c = 3;
904                long d = 4;
905                char e = 'x';
906                float f = 1.0f;
907                double g = 2.0;
908                boolean h = true;
909                boolean i = false;
910            }",
911            "foo.java",
912            // All 8 primitive-type keywords must appear as distinct operators.
913            // true/false appear as operands.
914            &mut [
915                "{}",
916                ";",
917                "=",
918                "byte",
919                "short",
920                "int",
921                "long",
922                "char",
923                "float",
924                "double",
925                "boolean_type",
926            ],
927            &mut [
928                "Prims", "a", "b", "c", "d", "e", "f", "g", "h", "i", "1", "2", "3", "4", "'x'",
929                "1.0f", "2.0", "true", "false",
930            ],
931        );
932    }
933
934    /// A `Unit` space must never carry the synthetic `<anonymous>`
935    /// placeholder that the default getter invents for nodes without a
936    /// `name` field. The public docs describe `None` as the
937    /// "name could not be resolved" state, and the metrics-side
938    /// `FuncSpace::new` already special-cases `SpaceKind::Unit` the same
939    /// way; this pins the `Ops::new` mirror so a regression to the old
940    /// `Some("<anonymous>")` initialisation fails here rather than only
941    /// surfacing for a (currently unreachable) non-top-level `Unit`
942    /// space, where `ops_inner`'s top-level override would not rescue it.
943    /// See issue #755.
944    #[cfg(feature = "rust")]
945    #[test]
946    fn unit_space_name_is_none_not_anonymous() {
947        use crate::getter::Getter;
948        use crate::node::Ancestors;
949        use crate::traits::ParserTrait;
950        use crate::{RustCode, RustParser, SpaceKind};
951
952        let code = b"fn f() {}\n";
953        let parser = RustParser::new(code.to_vec(), std::path::Path::new("foo.rs"), None);
954        let root = parser.root();
955        // The Rust `source_file` root is a `Unit` and has no `name`/`type`
956        // field, so the default getter would invent `<anonymous>`.
957        assert_eq!(SpaceKind::Unit, RustCode::get_space_kind(&root));
958
959        let ops = super::Ops::new::<RustCode>(&root, code, Ancestors::unknown(), SpaceKind::Unit);
960        assert_eq!(
961            ops.name, None,
962            "Unit space must preserve name = None, not invent <anonymous>"
963        );
964    }
965
966    /// Issue #789: an `ERROR`-root parse (here Lua partial input) where
967    /// `metrics()` succeeds must make `ops()` succeed too — the two seams
968    /// should agree. Before the synthetic-Unit-root mirror in `ops_inner`,
969    /// `ops()` returned `Err(MetricsError::EmptyRoot)` because the ERROR
970    /// root is not classified as a function space, so no frame was ever
971    /// pushed. This pins their agreement: both succeed, and the resulting
972    /// top-level `Ops` is a `Unit` whose name is the caller-supplied
973    /// `Source::name` (the intrinsic Unit name stays `None` per #755 until
974    /// `ops_inner` overrides the top-level name).
975    #[cfg(feature = "lua")]
976    #[test]
977    fn lua_error_root_ops_agrees_with_metrics_789() {
978        use crate::{MetricsOptions, SpaceKind};
979
980        // tree-sitter-lua surfaces an ERROR root for this partial input.
981        let src = b"function foo(x)\n  return x +\n".to_vec();
982        let name = "partial.lua".to_owned();
983
984        let ast = Ast::parse(Source::new(LANG::Lua, &src).with_name(Some(name.clone())))
985            .expect("lua feature enabled");
986
987        // metrics() must succeed (it already wrapped a synthetic Unit root).
988        let space = ast
989            .metrics(MetricsOptions::default())
990            .expect("metrics must yield a top-level space");
991        assert_eq!(space.kind, SpaceKind::Unit);
992
993        // ops() must now succeed in the same case rather than returning
994        // Err(EmptyRoot).
995        let ops = ast
996            .ops()
997            .expect("ops must agree with metrics and yield a top-level Ops");
998        assert_eq!(ops.kind, SpaceKind::Unit);
999        assert_eq!(
1000            ops.name.as_deref(),
1001            Some(name.as_str()),
1002            "top-level Ops name is the caller-supplied Source::name"
1003        );
1004    }
1005
1006    /// Issue #790: `Ops::operands` / `Ops::operators` are the *distinct*
1007    /// (deduplicated) Halstead operand/operator vocabularies (`n2` / `n1`),
1008    /// not every occurrence. Pin the documented dedup semantics: each
1009    /// vector's length equals its unique-element count. The fixture
1010    /// repeats `+`, `;`, and `=` operators and the `a` operand so a
1011    /// regression to non-deduplicated collection would make `len` exceed
1012    /// the unique count.
1013    #[cfg(feature = "rust")]
1014    #[test]
1015    fn ops_vocabularies_are_distinct_790() {
1016        use std::collections::HashSet;
1017
1018        let src = b"fn main() { let a = 1 + 1; let b = a + a; }\n".to_vec();
1019        let ops = Ast::parse(Source::new(LANG::Rust, &src).with_name(Some("foo.rs".to_owned())))
1020            .expect("rust feature enabled")
1021            .ops()
1022            .expect("ops walk must yield a top-level Ops");
1023
1024        let unique_operators: HashSet<&String> = ops.operators.iter().collect();
1025        assert_eq!(
1026            ops.operators.len(),
1027            unique_operators.len(),
1028            "Ops::operators must be the distinct operator vocabulary (n1)"
1029        );
1030
1031        let unique_operands: HashSet<&String> = ops.operands.iter().collect();
1032        assert_eq!(
1033            ops.operands.len(),
1034            unique_operands.len(),
1035            "Ops::operands must be the distinct operand vocabulary (n2)"
1036        );
1037    }
1038
1039    /// Assert that every space in the tree carries sorted vocabularies,
1040    /// and return how many spaces were checked so a caller can prove the
1041    /// walk actually descended.
1042    ///
1043    /// The length floor is what keeps this from going quietly vacuous:
1044    /// `is_sorted` is trivially true for an empty or single-entry
1045    /// vector, so without it a fixture that stopped producing real
1046    /// vocabularies would keep passing while covering nothing.
1047    fn assert_sorted_spaces(ops: &Ops, lang: LANG) -> usize {
1048        /// Smallest vocabulary in which an ordering is observable.
1049        const MIN_OBSERVABLE: usize = 2;
1050
1051        let mut stack = vec![ops];
1052        let mut visited = 0;
1053
1054        while let Some(space) = stack.pop() {
1055            visited += 1;
1056            for (field, values) in [
1057                ("operators", &space.operators),
1058                ("operands", &space.operands),
1059            ] {
1060                assert!(
1061                    values.len() >= MIN_OBSERVABLE && values.is_sorted(),
1062                    "{lang:?} {field} of space {:?} (@{}) must hold at least \
1063                     {MIN_OBSERVABLE} entries and be sorted: {values:?}",
1064                    space.name,
1065                    space.start_line
1066                );
1067            }
1068            stack.extend(space.spaces.iter());
1069        }
1070
1071        visited
1072    }
1073
1074    /// Every space's vocabularies come back sorted, in every language.
1075    ///
1076    /// The operator vocabulary is the union of two maps — one keyed by
1077    /// token id, one keyed by text, which is where primitive types such
1078    /// as C++ `int` land — and sorting is what interleaves them rather
1079    /// than leaving the second concatenated onto the first (#1091). The
1080    /// `spans_both_maps` pair per case names one entry from each map, so
1081    /// a fixture that stopped exercising the text-keyed map fails here
1082    /// instead of silently narrowing the test's reach.
1083    #[test]
1084    fn ops_vocabularies_are_sorted_1091() {
1085        /// `(language, file name, source, (text-keyed operator,
1086        /// token-id-keyed operator that must sort after it))`.
1087        type Case = (
1088            LANG,
1089            &'static str,
1090            &'static str,
1091            (&'static str, &'static str),
1092        );
1093
1094        let cases: &[Case] = &[
1095            #[cfg(feature = "rust")]
1096            (
1097                LANG::Rust,
1098                "rust.rs",
1099                "fn zeta(quux: u32) -> u32 { let mid = quux + 1; \
1100                 let alpha = |beta: u32| beta * mid; alpha(mid) - quux }\n",
1101                ("u32", "|"),
1102            ),
1103            #[cfg(feature = "cpp")]
1104            (
1105                LANG::Cpp,
1106                "cpp.cpp",
1107                "int zeta(int quux) { double mid = quux + 1; \
1108                 char alpha = 'z'; return quux - mid + alpha; }\n",
1109                ("int", "return"),
1110            ),
1111            #[cfg(feature = "java")]
1112            (
1113                LANG::Java,
1114                "Java.java",
1115                "class Zeta { int quux(int mid) { long alpha = mid + 1; \
1116                 boolean beta = alpha > 2; return beta ? mid : 0; } }\n",
1117                ("long", "return"),
1118            ),
1119            #[cfg(feature = "python")]
1120            (
1121                LANG::Python,
1122                "python.py",
1123                "def zeta(quux):\n    mid = quux + 1\n    \
1124                 def alpha(beta):\n        return beta * mid\n    return alpha(mid) - quux\n",
1125                // Python has no primitive-type operators; both entries
1126                // come from the token-id map, so this pair only pins the
1127                // ordering, not the interleaving.
1128                ("def", "return"),
1129            ),
1130            #[cfg(feature = "typescript")]
1131            (
1132                LANG::Typescript,
1133                "ts.ts",
1134                "function zeta(quux: number): number { const mid: number = quux + 1; \
1135                 const alpha = (beta: number) => beta * mid; return alpha(mid) - quux; }\n",
1136                ("number", "return"),
1137            ),
1138        ];
1139
1140        for (lang, file, source, (from_text_map, sorts_after)) in cases {
1141            let ops = Ast::parse(
1142                Source::new(*lang, source.as_bytes()).with_name(Some((*file).to_owned())),
1143            )
1144            .expect("language feature enabled")
1145            .ops()
1146            .expect("ops walk must yield a top-level Ops");
1147
1148            let position = |needle: &str| {
1149                ops.operators
1150                    .iter()
1151                    .position(|op| op == needle)
1152                    .unwrap_or_else(|| {
1153                        panic!(
1154                            "{lang:?} operators must contain {needle:?}: {:?}",
1155                            ops.operators
1156                        )
1157                    })
1158            };
1159            assert!(
1160                position(from_text_map) < position(sorts_after),
1161                "{lang:?} must order {from_text_map:?} before {sorts_after:?}: {:?}",
1162                ops.operators
1163            );
1164
1165            assert!(
1166                assert_sorted_spaces(&ops, *lang) > 1,
1167                "{lang:?} sample must nest at least one sub-space"
1168            );
1169        }
1170    }
1171
1172    /// Two parses of the same bytes in one process must agree exactly.
1173    ///
1174    /// `RandomState` bumps its thread-local seed per instance, so the
1175    /// pre-fix code could — and did — order two `HashMap`s built from
1176    /// identical keys differently within a single run. This is the
1177    /// in-process form of the cross-run churn in #1091.
1178    #[test]
1179    #[cfg(feature = "rust")]
1180    fn ops_are_stable_across_repeated_parses_1091() {
1181        use std::fmt::Write as _;
1182
1183        // Enough distinct operands, in enough distinct spaces, that
1184        // agreement by coincidence is not a plausible explanation for a
1185        // pass.
1186        let mut src = String::new();
1187        for i in 0..40 {
1188            writeln!(src, "fn name{i}(arg{i}: u32) -> u32 {{ arg{i} + {i} }}")
1189                .expect("writing to a String cannot fail");
1190        }
1191
1192        let parse = || {
1193            Ast::parse(Source::new(LANG::Rust, src.as_bytes()).with_name(Some("foo.rs".to_owned())))
1194                .expect("rust feature enabled")
1195                .ops()
1196                .expect("ops walk must yield a top-level Ops")
1197        };
1198
1199        let (first, second) = (parse(), parse());
1200        assert!(
1201            first.operands.len() >= 40 && first.spaces.len() >= 40,
1202            "sample must have a wide vocabulary across many spaces, got {} operands \
1203             in {} spaces",
1204            first.operands.len(),
1205            first.spaces.len()
1206        );
1207        // `Ops` has no `PartialEq`, and the nested spaces are the half a
1208        // top-level vector comparison would miss, so compare the whole
1209        // serialized tree.
1210        let render =
1211            |ops: &Ops| serde_json::to_string(&ops.to_wire()).expect("wire Ops serializes to JSON");
1212        assert_eq!(render(&first), render(&second));
1213    }
1214
1215    /// A vocabulary that lost bytes is ordered by its *rendered* text.
1216    ///
1217    /// #1110 moved the sort ahead of the lossy UTF-8 rendering, which is
1218    /// only order-preserving while every key is valid UTF-8. Here it is
1219    /// not: the two string operands are `"\xffA"` and `"\u{fffd}B"`, so
1220    /// by raw bytes the first sorts *after* the second (`0xff` > `0xef`)
1221    /// and by rendered text — both start `U+FFFD`, then `A` before `B` —
1222    /// it sorts before. The rendered order is what the pre-#1110
1223    /// render-then-sort code produced and what `Ops` documents, so
1224    /// dropping the fallback re-sort flips this pair and fails here.
1225    #[test]
1226    #[cfg(feature = "rust")]
1227    fn ops_vocabulary_orders_lossy_entries_by_rendered_text_1110() {
1228        let mut src = b"fn f() { let a = \"".to_vec();
1229        src.push(0xff);
1230        src.extend_from_slice(b"A\"; let b = \"");
1231        src.extend_from_slice(&[0xef, 0xbf, 0xbd]);
1232        src.extend_from_slice(b"B\"; }\n");
1233
1234        let ops = Ast::parse(Source::new(LANG::Rust, &src).with_name(Some("foo.rs".to_owned())))
1235            .expect("rust feature enabled")
1236            .ops()
1237            .expect("ops walk must yield a top-level Ops");
1238
1239        let position = |needle: &str| {
1240            ops.operands
1241                .iter()
1242                .position(|operand| operand == needle)
1243                .unwrap_or_else(|| panic!("operands must contain {needle:?}: {:?}", ops.operands))
1244        };
1245        assert!(
1246            position("\"\u{fffd}A\"") < position("\"\u{fffd}B\""),
1247            "lossy entries must be ordered by rendered text, got {:?}",
1248            ops.operands
1249        );
1250        assert!(
1251            ops.operands.is_sorted(),
1252            "the whole vocabulary must be sorted as rendered, got {:?}",
1253            ops.operands
1254        );
1255    }
1256
1257    /// The walk classifies a space kind once per space, not once per node.
1258    ///
1259    /// Nothing in the output distinguishes the two: the classification
1260    /// only ever reaches `Ops::new`, so running it on every node produces
1261    /// the same tree and merely throws the extra answers away. #1110
1262    /// moved the call inside the `func_space` branch, mirroring
1263    /// `spaces::compute::open_func_space`; the counter is what makes
1264    /// hoisting it back out a failure. The node-count assertion is what
1265    /// makes the counts distinguishable — a fixture whose nodes and
1266    /// spaces were equal in number could not tell the two apart.
1267    // test-lang-gates: hand-written(rust) — the one grammar that
1268    //     makes the fixture list non-empty, so the non-vacuity
1269    //     assertion cannot fire on a minimal build
1270    #[test]
1271    // Gated on the language that guarantees a non-empty case list, so
1272    // the emptiness assertion below cannot fire on a minimal build.
1273    #[cfg(feature = "rust")]
1274    fn ops_classifies_space_kind_once_per_space_1110() {
1275        let cases: &[(LANG, &str, &str)] = &[
1276            #[cfg(feature = "rust")]
1277            (
1278                LANG::Rust,
1279                "foo.rs",
1280                "fn outer(a: u32) -> u32 { fn inner(b: u32) -> u32 { b + 1 } inner(a) * 2 }\n",
1281            ),
1282            #[cfg(feature = "python")]
1283            (
1284                LANG::Python,
1285                "foo.py",
1286                "def outer(a):\n    def inner(b):\n        return b + 1\n    return inner(a) * 2\n",
1287            ),
1288            #[cfg(feature = "cpp")]
1289            (
1290                LANG::Cpp,
1291                "foo.cpp",
1292                "struct S { int m(int a) { return a + 1; } }; int f(int b) { return b * 2; }\n",
1293            ),
1294            #[cfg(feature = "java")]
1295            (
1296                LANG::Java,
1297                "Foo.java",
1298                "class C { int m(int a) { return a + 1; } int n(int b) { return b * 2; } }\n",
1299            ),
1300            #[cfg(feature = "javascript")]
1301            (
1302                LANG::Javascript,
1303                "foo.js",
1304                "function outer(a) { function inner(b) { return b + 1; } return inner(a) * 2; }\n",
1305            ),
1306        ];
1307        crate::test_support::assert_fixtures_present(cases);
1308
1309        for (lang, file, source) in cases {
1310            let ast = crate::test_support::parse_named(*lang, file, source);
1311
1312            let before = super::space_kind_lookups::observed();
1313            let ops = ast.ops().expect("ops walk must yield a top-level Ops");
1314            let lookups = super::space_kind_lookups::observed() - before;
1315
1316            let mut spaces = 0;
1317            let mut stack = vec![&ops];
1318            while let Some(space) = stack.pop() {
1319                spaces += 1;
1320                stack.extend(space.spaces.iter());
1321            }
1322
1323            let mut nodes = 0;
1324            let mut cursor = vec![ast.as_tree_sitter().root_node()];
1325            while let Some(node) = cursor.pop() {
1326                nodes += 1;
1327                let mut walker = node.walk();
1328                cursor.extend(node.children(&mut walker));
1329            }
1330
1331            assert!(
1332                nodes > spaces * 4,
1333                "{lang:?} fixture must have many more nodes ({nodes}) than spaces ({spaces}) \
1334                 for the two counts to be distinguishable"
1335            );
1336            assert_eq!(
1337                lookups, spaces,
1338                "{lang:?} must classify once per space, not once per node ({nodes} nodes)"
1339            );
1340        }
1341    }
1342
1343    /// One flattened space: `(depth, kind, name, start_line, end_line)`.
1344    #[cfg(feature = "elixir")]
1345    type FlatSpace = (usize, crate::SpaceKind, String, usize, usize);
1346
1347    /// Flattens an `Ops` tree in preorder, so a test can pin the whole
1348    /// tree in one `assert_eq!` and see the surrounding spaces when one
1349    /// is wrong.
1350    ///
1351    /// `end_line` is carried as well as `start_line` because a change to
1352    /// the promote predicate can move a space's *extent* without moving
1353    /// its head — a `def` that swallows its sibling would keep the same
1354    /// start line.
1355    #[cfg(feature = "elixir")]
1356    fn flatten(ops: &Ops, depth: usize, out: &mut Vec<FlatSpace>) {
1357        out.push((
1358            depth,
1359            ops.kind,
1360            ops.name.clone().unwrap_or_else(|| "<none>".to_owned()),
1361            ops.start_line,
1362            ops.end_line,
1363        ));
1364        for child in &ops.spaces {
1365            flatten(child, depth + 1, out);
1366        }
1367    }
1368
1369    #[cfg(feature = "elixir")]
1370    fn elixir_ops_tree(source: &str) -> Vec<FlatSpace> {
1371        let ops = crate::test_support::parse_named(LANG::Elixir, "foo.ex", source)
1372            .ops()
1373            .expect("ops walk must yield a top-level Ops");
1374        let mut flat = Vec::new();
1375        flatten(&ops, 0, &mut flat);
1376        flat
1377    }
1378
1379    /// Issue #1130: Elixir's `defmodule` / `def` are `Call` nodes whose
1380    /// target identifier text spells the keyword, so only the
1381    /// source-aware promote predicate can recognise them. Before the
1382    /// fix `ops()` returned the bare file-level `Unit` for this input
1383    /// while `metrics()` returned the full module/function tree.
1384    #[cfg(feature = "elixir")]
1385    #[test]
1386    fn elixir_ops_opens_module_and_function_spaces_1130() {
1387        use crate::SpaceKind::{Class, Function, Unit};
1388
1389        assert_eq!(
1390            elixir_ops_tree("defmodule Foo do\n  def bar(x) do\n    x + 1\n  end\nend\n"),
1391            vec![
1392                (0, Unit, "foo.ex".to_owned(), 1, 5),
1393                (1, Class, "Foo".to_owned(), 1, 5),
1394                (2, Function, "bar".to_owned(), 2, 4),
1395            ],
1396        );
1397    }
1398
1399    /// An `AnonymousFunction` is the one Elixir space the byte-less
1400    /// predicate could already see, so this pins that the source-aware
1401    /// predicate did not lose it — and that it nests under the `def`
1402    /// space rather than being reparented to the file root.
1403    #[cfg(feature = "elixir")]
1404    #[test]
1405    fn elixir_ops_opens_anonymous_function_space() {
1406        use crate::SpaceKind::{Class, Function, Unit};
1407
1408        assert_eq!(
1409            elixir_ops_tree(
1410                "defmodule Foo do\n  def bar(list) do\n    \
1411                 Enum.map(list, fn x -> x * 2 end)\n  end\nend\n"
1412            ),
1413            vec![
1414                (0, Unit, "foo.ex".to_owned(), 1, 5),
1415                (1, Class, "Foo".to_owned(), 1, 5),
1416                (2, Function, "bar".to_owned(), 2, 4),
1417                (3, Function, "<anonymous>".to_owned(), 3, 3),
1418            ],
1419        );
1420    }
1421
1422    /// Issue #310: a `def` inside `quote do … end` is a code *template*
1423    /// emitted later by macro expansion, not a declaration of the
1424    /// enclosing module, so it opens no space. This is the case only the
1425    /// source-aware predicate can get right — the byte-less one never
1426    /// saw any `def` at all, so it was accidentally "correct" here while
1427    /// being wrong everywhere else.
1428    #[cfg(feature = "elixir")]
1429    #[test]
1430    fn elixir_ops_skips_def_inside_quote_block_310() {
1431        use crate::SpaceKind::{Class, Function, Unit};
1432
1433        // The quoted `def` heads line 4. Its name resolves to the
1434        // `<anonymous>` placeholder (the head is `unquote(name)`, not a
1435        // literal identifier), so the absence of a fourth entry — not a
1436        // name match — is what pins it out of the tree.
1437        assert_eq!(
1438            elixir_ops_tree(
1439                "defmodule Foo do\n  defmacro gen(name) do\n    quote do\n      \
1440                 def unquote(name)(x) do\n        x + 1\n      end\n    end\n  end\nend\n",
1441            ),
1442            vec![
1443                (0, Unit, "foo.ex".to_owned(), 1, 9),
1444                (1, Class, "Foo".to_owned(), 1, 9),
1445                (2, Function, "gen".to_owned(), 2, 8),
1446            ],
1447        );
1448    }
1449}