Add explicit read-only mixed source8 CLI checking

crates/oa-cli/src/lib.rs

@@ -170,6 +170,47 @@ fn disk_error(report: &mut Report, error: SourceFileError) {
     report.fail(3, code, error.to_string());
 }
 
+/// Validate captured mixed source8 bytes without creating an editable candidate.
+pub fn check_mixed(entry: &Path) -> Report {
+    let mut report = Report::empty(entry, "check-mixed");
+    let snapshot = match source_files::load_mixed_source(entry, LIMITS) {
+        Ok(snapshot) => snapshot,
+        Err(error) => {
+            disk_error(&mut report, error);
+            return report;
+        }
+    };
+    let diagnostics = if snapshot.diagnostics().is_empty() {
+        match language::check_mixed_bundle(snapshot.bundle(), LIMITS) {
+            Ok(checked) => checked.warnings().to_vec(),
+            Err(errors) => errors,
+        }
+    } else {
+        snapshot.diagnostics().to_vec()
+    };
+    if diagnostics
+        .iter()
+        .any(|d| d.diagnostic.severity == Severity::Error)
+    {
+        report.status = "invalid".into();
+        report.exit_code = if diagnostics.iter().any(|d| {
+            matches!(
+                d.diagnostic.code.as_str(),
+                "pending_save" | "missing_include" | "invalid_path"
+            )
+        }) {
+            3
+        } else {
+            1
+        };
+    }
+    report.diagnostics = diagnostics
+        .into_iter()
+        .map(|d| located(d, "input"))
+        .collect();
+    report
+}
+
 /// A candidate owns its original expectations and is consumed by saving.
 /// Callers cannot replace its source/model/expectations after preparation.
 pub struct Prepared {
@@ -406,14 +447,19 @@ fn unified_diff(path: &str, before: &str, after: &str) -> String {
     out
 }
 
+/// Read-only mixed checking cannot acquire ordinary edit/write authority.
+pub enum Dispatch {
+    Editable { operation: Operation, write: bool },
+    CheckMixed,
+}
+
 pub struct Arguments {
     pub entry: PathBuf,
-    pub operation: Operation,
-    pub write: bool,
+    pub dispatch: Dispatch,
     pub json: bool,
 }
 
-pub const HELP: &str = "arcadia check ROOT [--json]\narcadia lint ROOT [--json]\narcadia stabilize ROOT [--write] [--json]\narcadia rename-alias ROOT OLD NEW [--write] [--json]\n\nROOT is an explicit .arcadia entry file; includes resolve relative to it.\nMutation commands preview by default. --write applies this invocation's candidate.\nMissing UUIDs in a preview are provisional until written. No canonical formatting.\nExit: 0 valid/success (engineering warnings allowed), 1 invalid source or semantic\ncommand rejection, 2 usage, 3 disk/path/conflict/pending-journal/output failure.\nNo implicit journal recovery. Limits: 64 MiB, 256 files, include depth32/edges1024,\n100000 graph objects, 250000 records, 500000 ordered references.\n";
+pub const HELP: &str = "arcadia check ROOT [--json]\narcadia lint ROOT [--json]\narcadia check-mixed ROOT [--json]\narcadia stabilize ROOT [--write] [--json]\narcadia rename-alias ROOT OLD NEW [--write] [--json]\n\nROOT is an explicit .arcadia entry file; includes resolve relative to it.\ncheck-mixed requires source8 and explicit UUIDs; it never migrates, stabilizes or writes.\nMutation commands preview by default. --write applies this invocation's candidate.\nMissing UUIDs in a preview are provisional until written. No canonical formatting.\nExit: 0 valid/success (engineering warnings allowed), 1 invalid source or semantic\ncommand rejection, 2 usage, 3 disk/path/conflict/pending-journal/output failure.\nNo implicit journal recovery. Limits: 64 MiB, 256 files, include depth32/edges1024,\n100000 graph objects, 250000 records, 500000 ordered references.\n";
 
 pub fn arguments(args: &[std::ffi::OsString]) -> Result<Arguments, String> {
     let mut positional = Vec::new();
@@ -433,19 +479,28 @@ pub fn arguments(args: &[std::ffi::OsString]) -> Result<Arguments, String> {
         }
     }
     let command = positional.first().and_then(|s| s.to_str()).unwrap_or("");
-    let operation = match (command, positional.len()) {
-        ("check" | "lint", 2) if !write => Operation::Check,
-        ("stabilize", 2) => Operation::Stabilize,
-        ("rename-alias", 4) => Operation::RenameAlias {
-            old: positional[2].to_str().ok_or("Alias must be UTF-8")?.into(),
-            new: positional[3].to_str().ok_or("Alias must be UTF-8")?.into(),
+    let dispatch = match (command, positional.len()) {
+        ("check-mixed", 2) if !write => Dispatch::CheckMixed,
+        ("check" | "lint", 2) if !write => Dispatch::Editable {
+            operation: Operation::Check,
+            write,
+        },
+        ("stabilize", 2) => Dispatch::Editable {
+            operation: Operation::Stabilize,
+            write,
+        },
+        ("rename-alias", 4) => Dispatch::Editable {
+            operation: Operation::RenameAlias {
+                old: positional[2].to_str().ok_or("Alias must be UTF-8")?.into(),
+                new: positional[3].to_str().ok_or("Alias must be UTF-8")?.into(),
+            },
+            write,
         },
         _ => return Err(HELP.into()),
     };
     Ok(Arguments {
         entry: PathBuf::from(positional[1]),
-        operation,
-        write,
+        dispatch,
         json,
     })
 }

crates/oa-cli/src/main.rs

@@ -1,4 +1,4 @@
-use oa_cli::{Report, arguments, prepare};
+use oa_cli::{Dispatch, Report, arguments, check_mixed, prepare};
 use std::{
     io::{self, Write},
     path::Path,
@@ -26,13 +26,21 @@ fn human_report(report: &Report, show_diff: bool) -> io::Result<()> {
             d.severity, d.code, d.coordinate_space, d.message
         )?;
     }
-    writeln!(
-        err,
-        "{}: {} file changes; {} identities to stabilize",
-        report.status,
-        report.changes.len(),
-        report.identities_to_stabilize
-    )?;
+    if report.operation == "check-mixed" {
+        writeln!(
+            err,
+            "{}: mixed source8 check; no files changed",
+            report.status
+        )?;
+    } else {
+        writeln!(
+            err,
+            "{}: {} file changes; {} identities to stabilize",
+            report.status,
+            report.changes.len(),
+            report.identities_to_stabilize
+        )?;
+    }
     if let Some(migration) = &report.migration {
         writeln!(
             err,
@@ -67,19 +75,22 @@ fn run() -> io::Result<u8> {
     let mut displayed = false;
     let report = match arguments(&args) {
         Err(error) => Report::failure(Path::new(""), "usage", 2, "usage", error),
-        Ok(args) => match prepare(&args.entry, args.operation) {
-            Err(report) => *report,
-            Ok(prepared) => {
-                if args.write {
-                    if !args.json {
-                        human_report(prepared.report(), true)?;
-                        displayed = true;
+        Ok(args) => match args.dispatch {
+            Dispatch::CheckMixed => check_mixed(&args.entry),
+            Dispatch::Editable { operation, write } => match prepare(&args.entry, operation) {
+                Err(report) => *report,
+                Ok(prepared) => {
+                    if write {
+                        if !args.json {
+                            human_report(prepared.report(), true)?;
+                            displayed = true;
+                        }
+                        prepared.write()
+                    } else {
+                        prepared.into_report()
                     }
-                    prepared.write()
-                } else {
-                    prepared.into_report()
                 }
-            }
+            },
         },
     };
     if json {