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fallow_core/
lib.rs

1//! fallow-core is the internal implementation crate behind the `fallow`
2//! analyzer. External embedders should consume the curated programmatic
3//! surface at `fallow_cli::programmatic` (e.g. `detect_dead_code`,
4//! `detect_boundary_violations`, `detect_duplication`, `compute_complexity`,
5//! `compute_health`); each returns a `serde_json::Value` matching the CLI's
6//! `--format json` shape plus structured `ProgrammaticError` with the CLI's
7//! exit-code ladder. See `decisions/008-fallow-core-internal-policy.md` for
8//! the policy, and `docs/fallow-core-migration.md` for the function-by-function
9//! migration map. Items in this crate may change in any release, including
10//! patch releases; a subsequent minor will flip `publish = false` so the crate
11//! is no longer fetchable from crates.io.
12
13pub mod analyze;
14pub mod cache;
15pub mod changed_files;
16pub mod churn;
17pub mod cross_reference;
18pub mod discover;
19pub mod duplicates;
20pub(crate) mod errors;
21mod external_style_usage;
22pub mod extract;
23pub mod git_env;
24pub mod plugins;
25pub(crate) mod progress;
26pub mod results;
27pub(crate) mod scripts;
28pub mod suppress;
29pub mod trace;
30
31// Re-export from fallow-graph for backwards compatibility
32pub use fallow_graph::graph;
33pub use fallow_graph::project;
34pub use fallow_graph::resolve;
35
36use std::path::Path;
37use std::time::Instant;
38
39use errors::FallowError;
40use fallow_config::{
41    EntryPointRole, PackageJson, ResolvedConfig, discover_workspaces,
42    find_undeclared_workspaces_with_ignores,
43};
44use rayon::prelude::*;
45use results::AnalysisResults;
46use rustc_hash::FxHashSet;
47use trace::PipelineTimings;
48
49const UNDECLARED_WORKSPACE_WARNING_PREVIEW: usize = 5;
50type LoadedWorkspacePackage<'a> = (&'a fallow_config::WorkspaceInfo, PackageJson);
51
52fn record_graph_package_usage(
53    graph: &mut graph::ModuleGraph,
54    package_name: &str,
55    file_id: discover::FileId,
56    is_type_only: bool,
57) {
58    graph
59        .package_usage
60        .entry(package_name.to_owned())
61        .or_default()
62        .push(file_id);
63    if is_type_only {
64        graph
65            .type_only_package_usage
66            .entry(package_name.to_owned())
67            .or_default()
68            .push(file_id);
69    }
70}
71
72fn workspace_package_name<'a>(
73    source: &str,
74    workspace_names: &'a FxHashSet<&str>,
75) -> Option<&'a str> {
76    if !resolve::is_bare_specifier(source) {
77        return None;
78    }
79    let package_name = resolve::extract_package_name(source);
80    workspace_names.get(package_name.as_str()).copied()
81}
82
83fn credit_workspace_package_usage(
84    graph: &mut graph::ModuleGraph,
85    resolved: &[resolve::ResolvedModule],
86    workspaces: &[fallow_config::WorkspaceInfo],
87) {
88    if workspaces.is_empty() {
89        return;
90    }
91
92    let workspace_names: FxHashSet<&str> = workspaces.iter().map(|ws| ws.name.as_str()).collect();
93    for module in resolved {
94        for import in module.all_resolved_imports() {
95            if matches!(import.target, resolve::ResolveResult::InternalModule(_))
96                && let Some(package_name) =
97                    workspace_package_name(&import.info.source, &workspace_names)
98            {
99                record_graph_package_usage(
100                    graph,
101                    package_name,
102                    module.file_id,
103                    import.info.is_type_only,
104                );
105            }
106        }
107
108        for re_export in &module.re_exports {
109            if matches!(re_export.target, resolve::ResolveResult::InternalModule(_))
110                && let Some(package_name) =
111                    workspace_package_name(&re_export.info.source, &workspace_names)
112            {
113                record_graph_package_usage(
114                    graph,
115                    package_name,
116                    module.file_id,
117                    re_export.info.is_type_only,
118                );
119            }
120        }
121    }
122}
123
124/// Result of the full analysis pipeline, including optional performance timings.
125pub struct AnalysisOutput {
126    pub results: AnalysisResults,
127    pub timings: Option<PipelineTimings>,
128    pub graph: Option<graph::ModuleGraph>,
129    /// Parsed modules from the pipeline, available when `retain_modules` is true.
130    /// Used by the combined command to share a single parse across dead-code and health.
131    pub modules: Option<Vec<extract::ModuleInfo>>,
132    /// Discovered files from the pipeline, available when `retain_modules` is true.
133    pub files: Option<Vec<discover::DiscoveredFile>>,
134    /// Package names invoked from package.json scripts and CI configs, mirroring
135    /// what the unused-deps detector consults. Populated for every pipeline run;
136    /// trace tooling reads it so `trace_dependency` agrees with `unused-deps` on
137    /// "used vs unused" instead of returning false-negatives for script-only deps.
138    pub script_used_packages: rustc_hash::FxHashSet<String>,
139}
140
141/// Update cache: write freshly parsed modules and refresh stale mtime/size entries.
142fn update_cache(
143    store: &mut cache::CacheStore,
144    modules: &[extract::ModuleInfo],
145    files: &[discover::DiscoveredFile],
146) {
147    for module in modules {
148        if let Some(file) = files.get(module.file_id.0 as usize) {
149            let (mt, sz) = file_mtime_and_size(&file.path);
150            // If content hash matches, just refresh mtime/size if stale (e.g. `touch`ed file)
151            if let Some(cached) = store.get_by_path_only(&file.path)
152                && cached.content_hash == module.content_hash
153            {
154                if cached.mtime_secs != mt || cached.file_size != sz {
155                    store.insert(&file.path, cache::module_to_cached(module, mt, sz));
156                }
157                continue;
158            }
159            store.insert(&file.path, cache::module_to_cached(module, mt, sz));
160        }
161    }
162    store.retain_paths(files);
163}
164
165/// Extract mtime (seconds since epoch) and file size from a path.
166fn file_mtime_and_size(path: &std::path::Path) -> (u64, u64) {
167    std::fs::metadata(path).map_or((0, 0), |m| {
168        let mt = m
169            .modified()
170            .ok()
171            .and_then(|t| t.duration_since(std::time::SystemTime::UNIX_EPOCH).ok())
172            .map_or(0, |d| d.as_secs());
173        (mt, m.len())
174    })
175}
176
177fn format_undeclared_workspace_warning(
178    root: &Path,
179    undeclared: &[fallow_config::WorkspaceDiagnostic],
180) -> Option<String> {
181    if undeclared.is_empty() {
182        return None;
183    }
184
185    let preview = undeclared
186        .iter()
187        .take(UNDECLARED_WORKSPACE_WARNING_PREVIEW)
188        .map(|diag| {
189            diag.path
190                .strip_prefix(root)
191                .unwrap_or(&diag.path)
192                .display()
193                .to_string()
194                .replace('\\', "/")
195        })
196        .collect::<Vec<_>>();
197    let remaining = undeclared
198        .len()
199        .saturating_sub(UNDECLARED_WORKSPACE_WARNING_PREVIEW);
200    let tail = if remaining > 0 {
201        format!(" (and {remaining} more)")
202    } else {
203        String::new()
204    };
205    let noun = if undeclared.len() == 1 {
206        "directory with package.json is"
207    } else {
208        "directories with package.json are"
209    };
210    let guidance = if undeclared.len() == 1 {
211        "Add that path to package.json workspaces or pnpm-workspace.yaml if it should be analyzed as a workspace."
212    } else {
213        "Add those paths to package.json workspaces or pnpm-workspace.yaml if they should be analyzed as workspaces."
214    };
215
216    Some(format!(
217        "{} {} not declared as {}: {}{}. {}",
218        undeclared.len(),
219        noun,
220        if undeclared.len() == 1 {
221            "a workspace"
222        } else {
223            "workspaces"
224        },
225        preview.join(", "),
226        tail,
227        guidance
228    ))
229}
230
231fn warn_undeclared_workspaces(
232    root: &Path,
233    workspaces_vec: &[fallow_config::WorkspaceInfo],
234    ignore_patterns: &globset::GlobSet,
235    quiet: bool,
236) {
237    if quiet {
238        return;
239    }
240
241    let undeclared = find_undeclared_workspaces_with_ignores(root, workspaces_vec, ignore_patterns);
242    if let Some(message) = format_undeclared_workspace_warning(root, &undeclared) {
243        tracing::warn!("{message}");
244    }
245}
246
247/// Run the full analysis pipeline.
248///
249/// # Errors
250///
251/// Returns an error if file discovery, parsing, or analysis fails.
252#[deprecated(
253    since = "2.76.0",
254    note = "fallow_core is internal; use fallow_cli::programmatic::detect_dead_code instead. NOTE: replacement returns serde_json::Value, not typed AnalysisResults. See docs/fallow-core-migration.md and ADR-008."
255)]
256pub fn analyze(config: &ResolvedConfig) -> Result<AnalysisResults, FallowError> {
257    let output = analyze_full(config, false, false, false, false)?;
258    Ok(output.results)
259}
260
261/// Run the full analysis pipeline with export usage collection (for LSP Code Lens).
262///
263/// # Errors
264///
265/// Returns an error if file discovery, parsing, or analysis fails.
266#[deprecated(
267    since = "2.76.0",
268    note = "fallow_core is internal; use fallow_cli::programmatic::detect_dead_code instead. NOTE: export-usage collection is not exposed in the programmatic surface today. See docs/fallow-core-migration.md and ADR-008."
269)]
270pub fn analyze_with_usages(config: &ResolvedConfig) -> Result<AnalysisResults, FallowError> {
271    let output = analyze_full(config, false, true, false, false)?;
272    Ok(output.results)
273}
274
275/// Run the full analysis pipeline with optional performance timings and graph retention.
276///
277/// # Errors
278///
279/// Returns an error if file discovery, parsing, or analysis fails.
280#[deprecated(
281    since = "2.76.0",
282    note = "fallow_core is internal; use fallow_cli::programmatic::detect_dead_code instead. NOTE: trace timings are not exposed in the programmatic surface today; use `fallow check --performance` for CLI-side timings. See docs/fallow-core-migration.md and ADR-008."
283)]
284pub fn analyze_with_trace(config: &ResolvedConfig) -> Result<AnalysisOutput, FallowError> {
285    analyze_full(config, true, false, false, false)
286}
287
288/// Run the full analysis pipeline, retaining parsed modules and discovered files.
289///
290/// Used by the combined command to share a single parse across dead-code and health.
291/// When `need_complexity` is true, the `ComplexityVisitor` runs during parsing so
292/// the returned modules contain per-function complexity data.
293///
294/// # Errors
295///
296/// Returns an error if file discovery, parsing, or analysis fails.
297#[deprecated(
298    since = "2.76.0",
299    note = "fallow_core is internal; use fallow_cli::programmatic::detect_dead_code instead. NOTE: combined-mode module retention is not exposed in the programmatic surface today. See docs/fallow-core-migration.md and ADR-008."
300)]
301pub fn analyze_retaining_modules(
302    config: &ResolvedConfig,
303    need_complexity: bool,
304    retain_graph: bool,
305) -> Result<AnalysisOutput, FallowError> {
306    analyze_full(config, retain_graph, false, need_complexity, true)
307}
308
309/// Run the analysis pipeline using pre-parsed modules, skipping the parsing stage.
310///
311/// This avoids re-parsing files when the caller already has a `ParseResult` (e.g., from
312/// `fallow_core::extract::parse_all_files`). Discovery, plugins, scripts, entry points,
313/// import resolution, graph construction, and dead code detection still run normally.
314/// The graph is always retained (needed for file scores).
315///
316/// # Errors
317///
318/// Returns an error if discovery, graph construction, or analysis fails.
319#[allow(
320    clippy::too_many_lines,
321    reason = "pipeline orchestration stays easier to audit in one place"
322)]
323#[deprecated(
324    since = "2.76.0",
325    note = "fallow_core is internal; use fallow_cli::programmatic::detect_dead_code instead. NOTE: pre-parsed module reuse is not exposed in the programmatic surface today. See docs/fallow-core-migration.md and ADR-008."
326)]
327pub fn analyze_with_parse_result(
328    config: &ResolvedConfig,
329    modules: &[extract::ModuleInfo],
330) -> Result<AnalysisOutput, FallowError> {
331    let _span = tracing::info_span!("fallow_analyze_with_parse_result").entered();
332    let pipeline_start = Instant::now();
333
334    let show_progress = !config.quiet
335        && std::io::IsTerminal::is_terminal(&std::io::stderr())
336        && matches!(
337            config.output,
338            fallow_config::OutputFormat::Human
339                | fallow_config::OutputFormat::Compact
340                | fallow_config::OutputFormat::Markdown
341        );
342    let progress = progress::AnalysisProgress::new(show_progress);
343
344    if !config.root.join("node_modules").is_dir() {
345        tracing::warn!(
346            "node_modules directory not found. Run `npm install` / `pnpm install` first for accurate results."
347        );
348    }
349
350    // Discover workspaces
351    let t = Instant::now();
352    let workspaces_vec = discover_workspaces(&config.root);
353    let workspaces_ms = t.elapsed().as_secs_f64() * 1000.0;
354    if !workspaces_vec.is_empty() {
355        tracing::info!(count = workspaces_vec.len(), "workspaces discovered");
356    }
357
358    // Warn about directories with package.json not declared as workspaces
359    warn_undeclared_workspaces(
360        &config.root,
361        &workspaces_vec,
362        &config.ignore_patterns,
363        config.quiet,
364    );
365    let root_pkg = load_root_package_json(config);
366    let discovery_hidden_dir_scopes =
367        discover::collect_hidden_dir_scopes(config, root_pkg.as_ref(), &workspaces_vec);
368
369    // Stage 1: Discover files (cheap — needed for file registry and resolution)
370    let t = Instant::now();
371    let pb = progress.stage_spinner("Discovering files...");
372    let discovered_files =
373        discover::discover_files_with_additional_hidden_dirs(config, &discovery_hidden_dir_scopes);
374    let discover_ms = t.elapsed().as_secs_f64() * 1000.0;
375    pb.finish_and_clear();
376
377    let project = project::ProjectState::new(discovered_files, workspaces_vec);
378    let files = project.files();
379    let workspaces = project.workspaces();
380    let workspace_pkgs = load_workspace_packages(workspaces);
381
382    // Stage 1.5: Run plugin system
383    let t = Instant::now();
384    let pb = progress.stage_spinner("Detecting plugins...");
385    let mut plugin_result = run_plugins(
386        config,
387        files,
388        workspaces,
389        root_pkg.as_ref(),
390        &workspace_pkgs,
391    );
392    let plugins_ms = t.elapsed().as_secs_f64() * 1000.0;
393    pb.finish_and_clear();
394
395    // Stage 1.6: Analyze package.json scripts
396    let t = Instant::now();
397    analyze_all_scripts(
398        config,
399        workspaces,
400        root_pkg.as_ref(),
401        &workspace_pkgs,
402        &mut plugin_result,
403    );
404    let scripts_ms = t.elapsed().as_secs_f64() * 1000.0;
405
406    // Stage 2: SKIPPED — using pre-parsed modules from caller
407
408    // Stage 3: Discover entry points
409    let t = Instant::now();
410    let entry_points = discover_all_entry_points(
411        config,
412        files,
413        workspaces,
414        root_pkg.as_ref(),
415        &workspace_pkgs,
416        &plugin_result,
417    );
418    let entry_points_ms = t.elapsed().as_secs_f64() * 1000.0;
419
420    // Compute entry-point summary before the graph consumes the entry_points vec
421    let ep_summary = summarize_entry_points(&entry_points.all);
422
423    // Stage 4: Resolve imports to file IDs
424    let t = Instant::now();
425    let pb = progress.stage_spinner("Resolving imports...");
426    let mut resolved = resolve::resolve_all_imports(
427        modules,
428        files,
429        workspaces,
430        &plugin_result.active_plugins,
431        &plugin_result.path_aliases,
432        &plugin_result.scss_include_paths,
433        &config.root,
434        &config.resolve.conditions,
435    );
436    external_style_usage::augment_external_style_package_usage(
437        &mut resolved,
438        config,
439        workspaces,
440        &plugin_result,
441    );
442    let resolve_ms = t.elapsed().as_secs_f64() * 1000.0;
443    pb.finish_and_clear();
444
445    // Stage 5: Build module graph
446    let t = Instant::now();
447    let pb = progress.stage_spinner("Building module graph...");
448    let mut graph = graph::ModuleGraph::build_with_reachability_roots(
449        &resolved,
450        &entry_points.all,
451        &entry_points.runtime,
452        &entry_points.test,
453        files,
454    );
455    credit_workspace_package_usage(&mut graph, &resolved, workspaces);
456    let graph_ms = t.elapsed().as_secs_f64() * 1000.0;
457    pb.finish_and_clear();
458
459    // Stage 6: Analyze for dead code
460    let t = Instant::now();
461    let pb = progress.stage_spinner("Analyzing...");
462    #[expect(
463        deprecated,
464        reason = "ADR-008 keeps workspace path-dependency calls while warning external fallow-core consumers"
465    )]
466    let mut result = analyze::find_dead_code_full(
467        &graph,
468        config,
469        &resolved,
470        Some(&plugin_result),
471        workspaces,
472        modules,
473        false,
474    );
475    let analyze_ms = t.elapsed().as_secs_f64() * 1000.0;
476    pb.finish_and_clear();
477    progress.finish();
478
479    result.entry_point_summary = Some(ep_summary);
480
481    let total_ms = pipeline_start.elapsed().as_secs_f64() * 1000.0;
482
483    tracing::debug!(
484        "\n┌─ Pipeline Profile (reuse) ─────────────────────\n\
485         │  discover files:   {:>8.1}ms  ({} files)\n\
486         │  workspaces:       {:>8.1}ms\n\
487         │  plugins:          {:>8.1}ms\n\
488         │  script analysis:  {:>8.1}ms\n\
489         │  parse/extract:    SKIPPED (reused {} modules)\n\
490         │  entry points:     {:>8.1}ms  ({} entries)\n\
491         │  resolve imports:  {:>8.1}ms\n\
492         │  build graph:      {:>8.1}ms\n\
493         │  analyze:          {:>8.1}ms\n\
494         │  ────────────────────────────────────────────\n\
495         │  TOTAL:            {:>8.1}ms\n\
496         └─────────────────────────────────────────────────",
497        discover_ms,
498        files.len(),
499        workspaces_ms,
500        plugins_ms,
501        scripts_ms,
502        modules.len(),
503        entry_points_ms,
504        entry_points.all.len(),
505        resolve_ms,
506        graph_ms,
507        analyze_ms,
508        total_ms,
509    );
510
511    let timings = Some(PipelineTimings {
512        discover_files_ms: discover_ms,
513        file_count: files.len(),
514        workspaces_ms,
515        workspace_count: workspaces.len(),
516        plugins_ms,
517        script_analysis_ms: scripts_ms,
518        parse_extract_ms: 0.0, // Skipped — modules were reused
519        module_count: modules.len(),
520        cache_hits: 0,
521        cache_misses: 0,
522        cache_update_ms: 0.0,
523        entry_points_ms,
524        entry_point_count: entry_points.all.len(),
525        resolve_imports_ms: resolve_ms,
526        build_graph_ms: graph_ms,
527        analyze_ms,
528        duplication_ms: None,
529        total_ms,
530    });
531
532    Ok(AnalysisOutput {
533        results: result,
534        timings,
535        graph: Some(graph),
536        modules: None,
537        files: None,
538        script_used_packages: plugin_result.script_used_packages.clone(),
539    })
540}
541
542#[expect(
543    clippy::unnecessary_wraps,
544    reason = "Result kept for future error handling"
545)]
546#[expect(
547    clippy::too_many_lines,
548    reason = "main pipeline function; sequential phases are held together for clarity"
549)]
550fn analyze_full(
551    config: &ResolvedConfig,
552    retain: bool,
553    collect_usages: bool,
554    need_complexity: bool,
555    retain_modules: bool,
556) -> Result<AnalysisOutput, FallowError> {
557    let _span = tracing::info_span!("fallow_analyze").entered();
558    let pipeline_start = Instant::now();
559
560    // Progress bars: enabled when not quiet, stderr is a terminal, and output is human-readable.
561    // Structured formats (JSON, SARIF) suppress spinners even on TTY — users piping structured
562    // output don't expect progress noise on stderr.
563    let show_progress = !config.quiet
564        && std::io::IsTerminal::is_terminal(&std::io::stderr())
565        && matches!(
566            config.output,
567            fallow_config::OutputFormat::Human
568                | fallow_config::OutputFormat::Compact
569                | fallow_config::OutputFormat::Markdown
570        );
571    let progress = progress::AnalysisProgress::new(show_progress);
572
573    // Warn if node_modules is missing — resolution will be severely degraded
574    if !config.root.join("node_modules").is_dir() {
575        tracing::warn!(
576            "node_modules directory not found. Run `npm install` / `pnpm install` first for accurate results."
577        );
578    }
579
580    // Discover workspaces if in a monorepo
581    let t = Instant::now();
582    let workspaces_vec = discover_workspaces(&config.root);
583    let workspaces_ms = t.elapsed().as_secs_f64() * 1000.0;
584    if !workspaces_vec.is_empty() {
585        tracing::info!(count = workspaces_vec.len(), "workspaces discovered");
586    }
587
588    // Warn about directories with package.json not declared as workspaces
589    warn_undeclared_workspaces(
590        &config.root,
591        &workspaces_vec,
592        &config.ignore_patterns,
593        config.quiet,
594    );
595    let root_pkg = load_root_package_json(config);
596    let discovery_hidden_dir_scopes =
597        discover::collect_hidden_dir_scopes(config, root_pkg.as_ref(), &workspaces_vec);
598
599    // Stage 1: Discover all source files
600    let t = Instant::now();
601    let pb = progress.stage_spinner("Discovering files...");
602    let discovered_files =
603        discover::discover_files_with_additional_hidden_dirs(config, &discovery_hidden_dir_scopes);
604    let discover_ms = t.elapsed().as_secs_f64() * 1000.0;
605    pb.finish_and_clear();
606
607    // Build ProjectState: owns the file registry with stable FileIds and workspace metadata.
608    // This is the foundation for cross-workspace resolution and future incremental analysis.
609    let project = project::ProjectState::new(discovered_files, workspaces_vec);
610    let files = project.files();
611    let workspaces = project.workspaces();
612    let workspace_pkgs = load_workspace_packages(workspaces);
613
614    // Stage 1.5: Run plugin system — parse config files, discover dynamic entries
615    let t = Instant::now();
616    let pb = progress.stage_spinner("Detecting plugins...");
617    let mut plugin_result = run_plugins(
618        config,
619        files,
620        workspaces,
621        root_pkg.as_ref(),
622        &workspace_pkgs,
623    );
624    let plugins_ms = t.elapsed().as_secs_f64() * 1000.0;
625    pb.finish_and_clear();
626
627    // Stage 1.6: Analyze package.json scripts for binary usage and config file refs
628    let t = Instant::now();
629    analyze_all_scripts(
630        config,
631        workspaces,
632        root_pkg.as_ref(),
633        &workspace_pkgs,
634        &mut plugin_result,
635    );
636    let scripts_ms = t.elapsed().as_secs_f64() * 1000.0;
637
638    // Stage 2: Parse all files in parallel and extract imports/exports
639    let t = Instant::now();
640    let pb = progress.stage_spinner(&format!("Parsing {} files...", files.len()));
641    let mut cache_store = if config.no_cache {
642        None
643    } else {
644        cache::CacheStore::load(&config.cache_dir)
645    };
646
647    let parse_result = extract::parse_all_files(files, cache_store.as_ref(), need_complexity);
648    let modules = parse_result.modules;
649    let cache_hits = parse_result.cache_hits;
650    let cache_misses = parse_result.cache_misses;
651    let parse_ms = t.elapsed().as_secs_f64() * 1000.0;
652    pb.finish_and_clear();
653
654    // Update cache with freshly parsed modules and refresh stale mtime/size entries.
655    let t = Instant::now();
656    if !config.no_cache {
657        let store = cache_store.get_or_insert_with(cache::CacheStore::new);
658        update_cache(store, &modules, files);
659        if let Err(e) = store.save(&config.cache_dir) {
660            tracing::warn!("Failed to save cache: {e}");
661        }
662    }
663    let cache_ms = t.elapsed().as_secs_f64() * 1000.0;
664
665    // Stage 3: Discover entry points (static patterns + plugin-discovered patterns)
666    let t = Instant::now();
667    let entry_points = discover_all_entry_points(
668        config,
669        files,
670        workspaces,
671        root_pkg.as_ref(),
672        &workspace_pkgs,
673        &plugin_result,
674    );
675    let entry_points_ms = t.elapsed().as_secs_f64() * 1000.0;
676
677    // Stage 4: Resolve imports to file IDs
678    let t = Instant::now();
679    let pb = progress.stage_spinner("Resolving imports...");
680    let mut resolved = resolve::resolve_all_imports(
681        &modules,
682        files,
683        workspaces,
684        &plugin_result.active_plugins,
685        &plugin_result.path_aliases,
686        &plugin_result.scss_include_paths,
687        &config.root,
688        &config.resolve.conditions,
689    );
690    external_style_usage::augment_external_style_package_usage(
691        &mut resolved,
692        config,
693        workspaces,
694        &plugin_result,
695    );
696    let resolve_ms = t.elapsed().as_secs_f64() * 1000.0;
697    pb.finish_and_clear();
698
699    // Stage 5: Build module graph
700    let t = Instant::now();
701    let pb = progress.stage_spinner("Building module graph...");
702    let mut graph = graph::ModuleGraph::build_with_reachability_roots(
703        &resolved,
704        &entry_points.all,
705        &entry_points.runtime,
706        &entry_points.test,
707        files,
708    );
709    credit_workspace_package_usage(&mut graph, &resolved, workspaces);
710    let graph_ms = t.elapsed().as_secs_f64() * 1000.0;
711    pb.finish_and_clear();
712
713    // Compute entry-point summary before the graph consumes the entry_points vec
714    let ep_summary = summarize_entry_points(&entry_points.all);
715
716    // Stage 6: Analyze for dead code (with plugin context and workspace info)
717    let t = Instant::now();
718    let pb = progress.stage_spinner("Analyzing...");
719    #[expect(
720        deprecated,
721        reason = "ADR-008 keeps workspace path-dependency calls while warning external fallow-core consumers"
722    )]
723    let mut result = analyze::find_dead_code_full(
724        &graph,
725        config,
726        &resolved,
727        Some(&plugin_result),
728        workspaces,
729        &modules,
730        collect_usages,
731    );
732    let analyze_ms = t.elapsed().as_secs_f64() * 1000.0;
733    pb.finish_and_clear();
734    progress.finish();
735
736    result.entry_point_summary = Some(ep_summary);
737
738    let total_ms = pipeline_start.elapsed().as_secs_f64() * 1000.0;
739
740    let cache_summary = if cache_hits > 0 {
741        format!(" ({cache_hits} cached, {cache_misses} parsed)")
742    } else {
743        String::new()
744    };
745
746    tracing::debug!(
747        "\n┌─ Pipeline Profile ─────────────────────────────\n\
748         │  discover files:   {:>8.1}ms  ({} files)\n\
749         │  workspaces:       {:>8.1}ms\n\
750         │  plugins:          {:>8.1}ms\n\
751         │  script analysis:  {:>8.1}ms\n\
752         │  parse/extract:    {:>8.1}ms  ({} modules{})\n\
753         │  cache update:     {:>8.1}ms\n\
754         │  entry points:     {:>8.1}ms  ({} entries)\n\
755         │  resolve imports:  {:>8.1}ms\n\
756         │  build graph:      {:>8.1}ms\n\
757         │  analyze:          {:>8.1}ms\n\
758         │  ────────────────────────────────────────────\n\
759         │  TOTAL:            {:>8.1}ms\n\
760         └─────────────────────────────────────────────────",
761        discover_ms,
762        files.len(),
763        workspaces_ms,
764        plugins_ms,
765        scripts_ms,
766        parse_ms,
767        modules.len(),
768        cache_summary,
769        cache_ms,
770        entry_points_ms,
771        entry_points.all.len(),
772        resolve_ms,
773        graph_ms,
774        analyze_ms,
775        total_ms,
776    );
777
778    let timings = if retain {
779        Some(PipelineTimings {
780            discover_files_ms: discover_ms,
781            file_count: files.len(),
782            workspaces_ms,
783            workspace_count: workspaces.len(),
784            plugins_ms,
785            script_analysis_ms: scripts_ms,
786            parse_extract_ms: parse_ms,
787            module_count: modules.len(),
788            cache_hits,
789            cache_misses,
790            cache_update_ms: cache_ms,
791            entry_points_ms,
792            entry_point_count: entry_points.all.len(),
793            resolve_imports_ms: resolve_ms,
794            build_graph_ms: graph_ms,
795            analyze_ms,
796            duplication_ms: None,
797            total_ms,
798        })
799    } else {
800        None
801    };
802
803    Ok(AnalysisOutput {
804        results: result,
805        timings,
806        graph: if retain { Some(graph) } else { None },
807        modules: if retain_modules { Some(modules) } else { None },
808        files: if retain_modules {
809            Some(files.to_vec())
810        } else {
811            None
812        },
813        script_used_packages: plugin_result.script_used_packages,
814    })
815}
816
817/// Analyze package.json scripts from root and all workspace packages.
818///
819/// Populates the plugin result with script-used packages and config file
820/// entry patterns. Also scans CI config files for binary invocations.
821fn load_root_package_json(config: &ResolvedConfig) -> Option<PackageJson> {
822    PackageJson::load(&config.root.join("package.json")).ok()
823}
824
825fn load_workspace_packages(
826    workspaces: &[fallow_config::WorkspaceInfo],
827) -> Vec<LoadedWorkspacePackage<'_>> {
828    workspaces
829        .iter()
830        .filter_map(|ws| {
831            PackageJson::load(&ws.root.join("package.json"))
832                .ok()
833                .map(|pkg| (ws, pkg))
834        })
835        .collect()
836}
837
838fn analyze_all_scripts(
839    config: &ResolvedConfig,
840    workspaces: &[fallow_config::WorkspaceInfo],
841    root_pkg: Option<&PackageJson>,
842    workspace_pkgs: &[LoadedWorkspacePackage<'_>],
843    plugin_result: &mut plugins::AggregatedPluginResult,
844) {
845    // Collect all dependency names to build the bin-name → package-name reverse map.
846    // This resolves binaries like "attw" to "@arethetypeswrong/cli" even without
847    // node_modules/.bin symlinks.
848    let mut all_dep_names: Vec<String> = Vec::new();
849    if let Some(pkg) = root_pkg {
850        all_dep_names.extend(pkg.all_dependency_names());
851    }
852    for (_, ws_pkg) in workspace_pkgs {
853        all_dep_names.extend(ws_pkg.all_dependency_names());
854    }
855    all_dep_names.sort_unstable();
856    all_dep_names.dedup();
857
858    // Probe node_modules/ at project root and each workspace root so non-hoisted
859    // deps (pnpm strict, Yarn workspaces) are also discovered.
860    let mut nm_roots: Vec<&std::path::Path> = Vec::new();
861    if config.root.join("node_modules").is_dir() {
862        nm_roots.push(&config.root);
863    }
864    for ws in workspaces {
865        if ws.root.join("node_modules").is_dir() {
866            nm_roots.push(&ws.root);
867        }
868    }
869    let bin_map = scripts::build_bin_to_package_map(&nm_roots, &all_dep_names);
870
871    if let Some(pkg) = root_pkg
872        && let Some(ref pkg_scripts) = pkg.scripts
873    {
874        let scripts_to_analyze = if config.production {
875            scripts::filter_production_scripts(pkg_scripts)
876        } else {
877            pkg_scripts.clone()
878        };
879        let script_analysis = scripts::analyze_scripts(&scripts_to_analyze, &config.root, &bin_map);
880        plugin_result.script_used_packages = script_analysis.used_packages;
881
882        for config_file in &script_analysis.config_files {
883            plugin_result
884                .discovered_always_used
885                .push((config_file.clone(), "scripts".to_string()));
886        }
887        for entry in &script_analysis.entry_files {
888            if let Some(pat) = scripts::normalize_script_entry_pattern("", entry) {
889                plugin_result
890                    .entry_patterns
891                    .push((plugins::PathRule::new(pat), "scripts".to_string()));
892            }
893        }
894    }
895    use rayon::prelude::*;
896    type WsScriptOut = (
897        Vec<String>,
898        Vec<(String, String)>,
899        Vec<(plugins::PathRule, String)>,
900    );
901    let ws_results: Vec<WsScriptOut> = workspace_pkgs
902        .par_iter()
903        .map(|(ws, ws_pkg)| {
904            let mut used_packages = Vec::new();
905            let mut discovered_always_used: Vec<(String, String)> = Vec::new();
906            let mut entry_patterns: Vec<(plugins::PathRule, String)> = Vec::new();
907            if let Some(ref ws_scripts) = ws_pkg.scripts {
908                let scripts_to_analyze = if config.production {
909                    scripts::filter_production_scripts(ws_scripts)
910                } else {
911                    ws_scripts.clone()
912                };
913                let ws_analysis = scripts::analyze_scripts(&scripts_to_analyze, &ws.root, &bin_map);
914                used_packages.extend(ws_analysis.used_packages);
915
916                let ws_prefix = ws
917                    .root
918                    .strip_prefix(&config.root)
919                    .unwrap_or(&ws.root)
920                    .to_string_lossy();
921                for config_file in &ws_analysis.config_files {
922                    discovered_always_used
923                        .push((format!("{ws_prefix}/{config_file}"), "scripts".to_string()));
924                }
925                for entry in &ws_analysis.entry_files {
926                    if let Some(pat) = scripts::normalize_script_entry_pattern(&ws_prefix, entry) {
927                        entry_patterns.push((plugins::PathRule::new(pat), "scripts".to_string()));
928                    }
929                }
930            }
931            (used_packages, discovered_always_used, entry_patterns)
932        })
933        .collect();
934    for (used_packages, discovered_always_used, entry_patterns) in ws_results {
935        plugin_result.script_used_packages.extend(used_packages);
936        plugin_result
937            .discovered_always_used
938            .extend(discovered_always_used);
939        plugin_result.entry_patterns.extend(entry_patterns);
940    }
941
942    // Scan CI config files for binary invocations and positional file references.
943    // Returns both packages used by CI tooling AND project-relative file paths
944    // referenced as command-line arguments (e.g., `node scripts/deploy.ts` in a
945    // GitHub Actions `run:` block) so the referenced files become reachable
946    // entry points. CI files always live at the project root, so file paths
947    // need no workspace-prefix transformation. See issue #195 (Case D).
948    let ci_analysis = scripts::ci::analyze_ci_files(&config.root, &bin_map);
949    plugin_result
950        .script_used_packages
951        .extend(ci_analysis.used_packages);
952    for entry in &ci_analysis.entry_files {
953        if let Some(pat) = scripts::normalize_script_entry_pattern("", entry) {
954            plugin_result
955                .entry_patterns
956                .push((plugins::PathRule::new(pat), "scripts".to_string()));
957        }
958    }
959    plugin_result
960        .entry_point_roles
961        .entry("scripts".to_string())
962        .or_insert(EntryPointRole::Support);
963}
964
965/// Discover all entry points from static patterns, workspaces, plugins, and infrastructure.
966fn discover_all_entry_points(
967    config: &ResolvedConfig,
968    files: &[discover::DiscoveredFile],
969    workspaces: &[fallow_config::WorkspaceInfo],
970    root_pkg: Option<&PackageJson>,
971    workspace_pkgs: &[LoadedWorkspacePackage<'_>],
972    plugin_result: &plugins::AggregatedPluginResult,
973) -> discover::CategorizedEntryPoints {
974    let mut entry_points = discover::CategorizedEntryPoints::default();
975    let root_discovery = discover::discover_entry_points_with_warnings_from_pkg(
976        config,
977        files,
978        root_pkg,
979        workspaces.is_empty(),
980    );
981
982    let workspace_pkg_by_root: rustc_hash::FxHashMap<std::path::PathBuf, &PackageJson> =
983        workspace_pkgs
984            .iter()
985            .map(|(ws, pkg)| (ws.root.clone(), pkg))
986            .collect();
987
988    let workspace_discovery: Vec<discover::EntryPointDiscovery> = workspaces
989        .par_iter()
990        .map(|ws| {
991            let pkg = workspace_pkg_by_root.get(&ws.root).copied();
992            discover::discover_workspace_entry_points_with_warnings_from_pkg(&ws.root, files, pkg)
993        })
994        .collect();
995    let mut skipped_entries = rustc_hash::FxHashMap::default();
996    entry_points.extend_runtime(root_discovery.entries);
997    for (path, count) in root_discovery.skipped_entries {
998        *skipped_entries.entry(path).or_insert(0) += count;
999    }
1000    let mut ws_entries = Vec::new();
1001    for workspace in workspace_discovery {
1002        ws_entries.extend(workspace.entries);
1003        for (path, count) in workspace.skipped_entries {
1004            *skipped_entries.entry(path).or_insert(0) += count;
1005        }
1006    }
1007    discover::warn_skipped_entry_summary(&skipped_entries);
1008    entry_points.extend_runtime(ws_entries);
1009
1010    let plugin_entries = discover::discover_plugin_entry_point_sets(plugin_result, config, files);
1011    entry_points.extend(plugin_entries);
1012
1013    let infra_entries = discover::discover_infrastructure_entry_points(&config.root);
1014    entry_points.extend_runtime(infra_entries);
1015
1016    // Add dynamically loaded files from config as entry points
1017    if !config.dynamically_loaded.is_empty() {
1018        let dynamic_entries = discover::discover_dynamically_loaded_entry_points(config, files);
1019        entry_points.extend_runtime(dynamic_entries);
1020    }
1021
1022    entry_points.dedup()
1023}
1024
1025/// Summarize entry points by source category for user-facing output.
1026fn summarize_entry_points(entry_points: &[discover::EntryPoint]) -> results::EntryPointSummary {
1027    let mut counts: rustc_hash::FxHashMap<String, usize> = rustc_hash::FxHashMap::default();
1028    for ep in entry_points {
1029        let category = match &ep.source {
1030            discover::EntryPointSource::PackageJsonMain
1031            | discover::EntryPointSource::PackageJsonModule
1032            | discover::EntryPointSource::PackageJsonExports
1033            | discover::EntryPointSource::PackageJsonBin
1034            | discover::EntryPointSource::PackageJsonScript => "package.json",
1035            discover::EntryPointSource::Plugin { .. } => "plugin",
1036            discover::EntryPointSource::TestFile => "test file",
1037            discover::EntryPointSource::DefaultIndex => "default index",
1038            discover::EntryPointSource::ManualEntry => "manual entry",
1039            discover::EntryPointSource::InfrastructureConfig => "config",
1040            discover::EntryPointSource::DynamicallyLoaded => "dynamically loaded",
1041        };
1042        *counts.entry(category.to_string()).or_insert(0) += 1;
1043    }
1044    let mut by_source: Vec<(String, usize)> = counts.into_iter().collect();
1045    by_source.sort_by(|a, b| b.1.cmp(&a.1).then_with(|| a.0.cmp(&b.0)));
1046    results::EntryPointSummary {
1047        total: entry_points.len(),
1048        by_source,
1049    }
1050}
1051
1052/// Run plugins for root project and all workspace packages.
1053fn run_plugins(
1054    config: &ResolvedConfig,
1055    files: &[discover::DiscoveredFile],
1056    workspaces: &[fallow_config::WorkspaceInfo],
1057    root_pkg: Option<&PackageJson>,
1058    workspace_pkgs: &[LoadedWorkspacePackage<'_>],
1059) -> plugins::AggregatedPluginResult {
1060    let registry = plugins::PluginRegistry::new(config.external_plugins.clone());
1061    let file_paths: Vec<std::path::PathBuf> = files.iter().map(|f| f.path.clone()).collect();
1062    let root_config_search_roots = collect_config_search_roots(&config.root, &file_paths);
1063    let root_config_search_root_refs: Vec<&Path> = root_config_search_roots
1064        .iter()
1065        .map(std::path::PathBuf::as_path)
1066        .collect();
1067
1068    // Run plugins for root project (full run with external plugins, inline config, etc.)
1069    let mut result = root_pkg.map_or_else(plugins::AggregatedPluginResult::default, |pkg| {
1070        registry.run_with_search_roots(
1071            pkg,
1072            &config.root,
1073            &file_paths,
1074            &root_config_search_root_refs,
1075            config.production,
1076        )
1077    });
1078
1079    if workspaces.is_empty() {
1080        return result;
1081    }
1082
1083    let root_active_plugins: rustc_hash::FxHashSet<&str> =
1084        result.active_plugins.iter().map(String::as_str).collect();
1085
1086    // Pre-compile config matchers once and bucket source files by workspace.
1087    // Workspace config matching can then scan only files below that workspace
1088    // instead of every project file for every active matcher.
1089    let precompiled_matchers = registry.precompile_config_matchers();
1090    let workspace_relative_files = bucket_files_by_workspace(workspace_pkgs, &file_paths);
1091
1092    // Run plugins for each workspace package in parallel, then merge results.
1093    let ws_results: Vec<_> = workspace_pkgs
1094        .par_iter()
1095        .zip(workspace_relative_files.par_iter())
1096        .filter_map(|((ws, ws_pkg), relative_files)| {
1097            let ws_result = registry.run_workspace_fast(
1098                ws_pkg,
1099                &ws.root,
1100                &config.root,
1101                &precompiled_matchers,
1102                relative_files,
1103                &root_active_plugins,
1104                config.production,
1105            );
1106            if ws_result.active_plugins.is_empty() {
1107                return None;
1108            }
1109            let ws_prefix = ws
1110                .root
1111                .strip_prefix(&config.root)
1112                .unwrap_or(&ws.root)
1113                .to_string_lossy()
1114                .into_owned();
1115            Some((ws_result, ws_prefix))
1116        })
1117        .collect();
1118
1119    // Merge workspace results sequentially (deterministic order via par_iter index stability)
1120    // Track seen names for O(1) dedup instead of O(n) Vec::contains
1121    let mut seen_plugins: rustc_hash::FxHashSet<String> =
1122        result.active_plugins.iter().cloned().collect();
1123    let mut seen_prefixes: rustc_hash::FxHashSet<String> =
1124        result.virtual_module_prefixes.iter().cloned().collect();
1125    let mut seen_generated: rustc_hash::FxHashSet<String> =
1126        result.generated_import_patterns.iter().cloned().collect();
1127    let mut seen_suffixes: rustc_hash::FxHashSet<String> =
1128        result.virtual_package_suffixes.iter().cloned().collect();
1129
1130    fn extend_unique(
1131        target: &mut Vec<String>,
1132        seen: &mut rustc_hash::FxHashSet<String>,
1133        items: Vec<String>,
1134    ) {
1135        for item in items {
1136            if seen.insert(item.clone()) {
1137                target.push(item);
1138            }
1139        }
1140    }
1141    for (ws_result, ws_prefix) in ws_results {
1142        // Prefix helper: workspace-relative patterns need the workspace prefix
1143        // to be matchable from the monorepo root. But patterns that are already
1144        // project-root-relative (e.g., from angular.json which uses absolute paths
1145        // like "apps/client/src/styles.css") should not be double-prefixed.
1146        let prefix_if_needed = |pat: &str| -> String {
1147            if pat.starts_with(ws_prefix.as_str()) || pat.starts_with('/') {
1148                pat.to_string()
1149            } else {
1150                format!("{ws_prefix}/{pat}")
1151            }
1152        };
1153
1154        for (rule, pname) in &ws_result.entry_patterns {
1155            result
1156                .entry_patterns
1157                .push((rule.prefixed(&ws_prefix), pname.clone()));
1158        }
1159        for (plugin_name, role) in ws_result.entry_point_roles {
1160            result.entry_point_roles.entry(plugin_name).or_insert(role);
1161        }
1162        for (pat, pname) in &ws_result.always_used {
1163            result
1164                .always_used
1165                .push((prefix_if_needed(pat), pname.clone()));
1166        }
1167        for (pat, pname) in &ws_result.discovered_always_used {
1168            result
1169                .discovered_always_used
1170                .push((prefix_if_needed(pat), pname.clone()));
1171        }
1172        for (pat, pname) in &ws_result.fixture_patterns {
1173            result
1174                .fixture_patterns
1175                .push((prefix_if_needed(pat), pname.clone()));
1176        }
1177        for rule in &ws_result.used_exports {
1178            result.used_exports.push(rule.prefixed(&ws_prefix));
1179        }
1180        // Merge active plugin names (deduplicated via HashSet)
1181        for plugin_name in ws_result.active_plugins {
1182            if !seen_plugins.contains(&plugin_name) {
1183                seen_plugins.insert(plugin_name.clone());
1184                result.active_plugins.push(plugin_name);
1185            }
1186        }
1187        // These don't need prefixing (absolute paths / package names)
1188        result
1189            .referenced_dependencies
1190            .extend(ws_result.referenced_dependencies);
1191        result.setup_files.extend(ws_result.setup_files);
1192        result
1193            .tooling_dependencies
1194            .extend(ws_result.tooling_dependencies);
1195        // Virtual import boundaries — prefixes (e.g., Docusaurus `@theme/`),
1196        // generated import patterns (e.g., SvelteKit `/$types`), and package-name
1197        // suffixes (e.g., Vitest `/__mocks__`) — match against import specifiers
1198        // or package names, never file paths, so no workspace prefix is applied.
1199        extend_unique(
1200            &mut result.virtual_module_prefixes,
1201            &mut seen_prefixes,
1202            ws_result.virtual_module_prefixes,
1203        );
1204        extend_unique(
1205            &mut result.generated_import_patterns,
1206            &mut seen_generated,
1207            ws_result.generated_import_patterns,
1208        );
1209        extend_unique(
1210            &mut result.virtual_package_suffixes,
1211            &mut seen_suffixes,
1212            ws_result.virtual_package_suffixes,
1213        );
1214        // Path aliases from workspace plugins (e.g., SvelteKit $lib/ → src/lib).
1215        // Prefix the replacement directory so it resolves from the monorepo root.
1216        for (prefix, replacement) in ws_result.path_aliases {
1217            result
1218                .path_aliases
1219                .push((prefix, format!("{ws_prefix}/{replacement}")));
1220        }
1221    }
1222
1223    result
1224}
1225
1226fn bucket_files_by_workspace(
1227    workspace_pkgs: &[LoadedWorkspacePackage<'_>],
1228    file_paths: &[std::path::PathBuf],
1229) -> Vec<Vec<(std::path::PathBuf, String)>> {
1230    let mut buckets = vec![Vec::new(); workspace_pkgs.len()];
1231
1232    for file_path in file_paths {
1233        for (idx, (ws, _)) in workspace_pkgs.iter().enumerate() {
1234            if let Ok(relative) = file_path.strip_prefix(&ws.root) {
1235                buckets[idx].push((file_path.clone(), relative.to_string_lossy().into_owned()));
1236                break;
1237            }
1238        }
1239    }
1240
1241    buckets
1242}
1243
1244fn collect_config_search_roots(
1245    root: &Path,
1246    file_paths: &[std::path::PathBuf],
1247) -> Vec<std::path::PathBuf> {
1248    let mut roots: rustc_hash::FxHashSet<std::path::PathBuf> = rustc_hash::FxHashSet::default();
1249    roots.insert(root.to_path_buf());
1250
1251    for file_path in file_paths {
1252        let mut current = file_path.parent();
1253        while let Some(dir) = current {
1254            if !dir.starts_with(root) {
1255                break;
1256            }
1257            roots.insert(dir.to_path_buf());
1258            if dir == root {
1259                break;
1260            }
1261            current = dir.parent();
1262        }
1263    }
1264
1265    let mut roots_vec: Vec<_> = roots.into_iter().collect();
1266    roots_vec.sort();
1267    roots_vec
1268}
1269
1270/// Run analysis on a project directory (with export usages for LSP Code Lens).
1271///
1272/// # Errors
1273///
1274/// Returns an error if config loading, file discovery, parsing, or analysis fails.
1275#[deprecated(
1276    since = "2.76.0",
1277    note = "fallow_core is internal; use fallow_cli::programmatic::detect_dead_code instead (build a `DeadCodeOptions { analysis: AnalysisOptions { root, ..default() }, ..default() }`). See docs/fallow-core-migration.md and ADR-008."
1278)]
1279pub fn analyze_project(root: &Path) -> Result<AnalysisResults, FallowError> {
1280    let config = default_config(root);
1281    #[expect(
1282        deprecated,
1283        reason = "ADR-008: thin wrapper, internal call into the same deprecated surface"
1284    )]
1285    analyze_with_usages(&config)
1286}
1287
1288/// Resolve the analysis config for a project, mirroring the CLI's `--config`
1289/// behavior when `config_path` is provided.
1290///
1291/// # Errors
1292///
1293/// Returns an error when an explicit config cannot be loaded or automatic
1294/// config discovery finds an invalid config.
1295pub fn config_for_project(
1296    root: &Path,
1297    config_path: Option<&Path>,
1298) -> Result<(ResolvedConfig, Option<std::path::PathBuf>), FallowError> {
1299    let user_config = if let Some(path) = config_path {
1300        Some((
1301            fallow_config::FallowConfig::load(path)
1302                .map_err(|e| FallowError::config(format!("{e:#}")))?,
1303            path.to_path_buf(),
1304        ))
1305    } else {
1306        fallow_config::FallowConfig::find_and_load(root).map_err(FallowError::config)?
1307    };
1308
1309    let config = match user_config {
1310        Some((mut config, path)) => {
1311            let dead_code_production = config
1312                .production
1313                .for_analysis(fallow_config::ProductionAnalysis::DeadCode);
1314            config.production = dead_code_production.into();
1315            (
1316                config.resolve(
1317                    root.to_path_buf(),
1318                    fallow_config::OutputFormat::Human,
1319                    num_cpus(),
1320                    false,
1321                    true, // quiet: LSP/programmatic callers don't need progress bars
1322                ),
1323                Some(path),
1324            )
1325        }
1326        None => (
1327            fallow_config::FallowConfig::default().resolve(
1328                root.to_path_buf(),
1329                fallow_config::OutputFormat::Human,
1330                num_cpus(),
1331                false,
1332                true,
1333            ),
1334            None,
1335        ),
1336    };
1337
1338    Ok(config)
1339}
1340
1341/// Create a default config for a project root.
1342///
1343/// `analyze_project` is the dead-code entry point used by the LSP and other
1344/// programmatic embedders. When the loaded config uses the per-analysis
1345/// production form (`production: { deadCode: true, ... }`), the production
1346/// flag must be flattened to the dead-code analysis here. Otherwise
1347/// `ResolvedConfig::resolve` calls `.global()` which returns false for the
1348/// per-analysis variant and the production-mode rule overrides
1349/// (`unused_dev_dependencies: off`, etc.) plus `resolved.production = true`
1350/// are silently dropped.
1351pub(crate) fn default_config(root: &Path) -> ResolvedConfig {
1352    config_for_project(root, None).map_or_else(
1353        |_| {
1354            fallow_config::FallowConfig::default().resolve(
1355                root.to_path_buf(),
1356                fallow_config::OutputFormat::Human,
1357                num_cpus(),
1358                false,
1359                true,
1360            )
1361        },
1362        |(config, _)| config,
1363    )
1364}
1365
1366fn num_cpus() -> usize {
1367    std::thread::available_parallelism().map_or(4, std::num::NonZeroUsize::get)
1368}
1369
1370#[cfg(test)]
1371mod tests {
1372    use super::{
1373        bucket_files_by_workspace, collect_config_search_roots, format_undeclared_workspace_warning,
1374    };
1375    use std::path::{Path, PathBuf};
1376
1377    use fallow_config::WorkspaceDiagnostic;
1378
1379    fn diag(root: &Path, relative: &str) -> WorkspaceDiagnostic {
1380        WorkspaceDiagnostic {
1381            path: root.join(relative),
1382            message: String::new(),
1383        }
1384    }
1385
1386    #[test]
1387    fn undeclared_workspace_warning_is_singular_for_one_path() {
1388        let root = Path::new("/repo");
1389        let warning = format_undeclared_workspace_warning(root, &[diag(root, "packages/api")])
1390            .expect("warning should be rendered");
1391
1392        assert_eq!(
1393            warning,
1394            "1 directory with package.json is not declared as a workspace: packages/api. Add that path to package.json workspaces or pnpm-workspace.yaml if it should be analyzed as a workspace."
1395        );
1396    }
1397
1398    #[test]
1399    fn undeclared_workspace_warning_summarizes_many_paths() {
1400        let root = PathBuf::from("/repo");
1401        let diagnostics = [
1402            "examples/a",
1403            "examples/b",
1404            "examples/c",
1405            "examples/d",
1406            "examples/e",
1407            "examples/f",
1408        ]
1409        .into_iter()
1410        .map(|path| diag(&root, path))
1411        .collect::<Vec<_>>();
1412
1413        let warning = format_undeclared_workspace_warning(&root, &diagnostics)
1414            .expect("warning should be rendered");
1415
1416        assert_eq!(
1417            warning,
1418            "6 directories with package.json are not declared as workspaces: examples/a, examples/b, examples/c, examples/d, examples/e (and 1 more). Add those paths to package.json workspaces or pnpm-workspace.yaml if they should be analyzed as workspaces."
1419        );
1420    }
1421
1422    #[test]
1423    fn collect_config_search_roots_includes_file_ancestors_once() {
1424        let root = PathBuf::from("/repo");
1425        let search_roots = collect_config_search_roots(
1426            &root,
1427            &[
1428                root.join("apps/query/src/main.ts"),
1429                root.join("packages/shared/lib/index.ts"),
1430            ],
1431        );
1432
1433        assert_eq!(
1434            search_roots,
1435            vec![
1436                root.clone(),
1437                root.join("apps"),
1438                root.join("apps/query"),
1439                root.join("apps/query/src"),
1440                root.join("packages"),
1441                root.join("packages/shared"),
1442                root.join("packages/shared/lib"),
1443            ]
1444        );
1445    }
1446
1447    #[test]
1448    fn bucket_files_by_workspace_uses_workspace_relative_paths() {
1449        let root = PathBuf::from("/repo");
1450        let ui = fallow_config::WorkspaceInfo {
1451            root: root.join("apps/ui"),
1452            name: "ui".to_string(),
1453            is_internal_dependency: false,
1454        };
1455        let api = fallow_config::WorkspaceInfo {
1456            root: root.join("apps/api"),
1457            name: "api".to_string(),
1458            is_internal_dependency: false,
1459        };
1460        let workspace_pkgs = vec![
1461            (
1462                &ui,
1463                fallow_config::PackageJson {
1464                    name: Some("ui".to_string()),
1465                    ..Default::default()
1466                },
1467            ),
1468            (
1469                &api,
1470                fallow_config::PackageJson {
1471                    name: Some("api".to_string()),
1472                    ..Default::default()
1473                },
1474            ),
1475        ];
1476        let files = vec![
1477            root.join("apps/ui/vite.config.ts"),
1478            root.join("apps/ui/src/main.ts"),
1479            root.join("apps/api/src/server.ts"),
1480            root.join("tools/build.ts"),
1481        ];
1482
1483        let buckets = bucket_files_by_workspace(&workspace_pkgs, &files);
1484
1485        assert_eq!(
1486            buckets[0],
1487            vec![
1488                (
1489                    root.join("apps/ui/vite.config.ts"),
1490                    "vite.config.ts".to_string()
1491                ),
1492                (root.join("apps/ui/src/main.ts"), "src/main.ts".to_string()),
1493            ]
1494        );
1495        assert_eq!(
1496            buckets[1],
1497            vec![(
1498                root.join("apps/api/src/server.ts"),
1499                "src/server.ts".to_string()
1500            )]
1501        );
1502    }
1503}