2 files changed, 86 insertions, 0 deletions
diff --git a/tests/drivers/borrow_diag_test.js b/tests/drivers/borrow_diag_test.js
new file mode 100644
index 0000000..93a7561
--- /dev/null
+++ b/tests/drivers/borrow_diag_test.js
@@ -0,0 +1,73 @@
+// borrow diagnostics in the editor: the server publishes the compiler's own messages
+// (the same check `zy` runs), with the range of the conflicting use and related
+// information for where the owner ended and where it was declared.
+// usage: node tests/drivers/borrow_diag_test.js path/to/zclsp [server arguments]
+const TIMEOUT_SCALE = Number(process.env.ZC_TEST_TIMEOUT_SCALE) || 1;
+const assert = require('assert');
+const cp = require('child_process');
+const path = require('path');
+const uri = 'file://' + path.resolve('tests/drivers/borrow-diag-fixture.zc');
+const frame = m => { const b = Buffer.from(JSON.stringify(m)); return Buffer.concat([Buffer.from(`Content-Length: ${b.length}\r\n\r\n`), b]); };
+function diagnose(text) {
+	const msgs = [
+		{ id: 1, method: 'initialize', params: {} },
+		{ method: 'textDocument/didOpen', params: { textDocument: { uri, languageId: 'zc', version: 1, text } } },
+		{ id: 2, method: 'shutdown' },
+		{ method: 'exit' }
+	].map(m => ({ jsonrpc: '2.0', ...m }));
+	const r = cp.spawnSync(process.argv[2], process.argv.slice(3), { input: Buffer.concat(msgs.map(frame)), timeout: 30000 * TIMEOUT_SCALE, maxBuffer: 32 << 20 });
+	assert.strictEqual(r.status, 0, String(r.stderr));
+	let b = r.stdout, last = null;
+	while (b.length) {
+		const e = b.indexOf('\r\n\r\n'); assert.ok(e >= 0);
+		const n = Number(/Content-Length:\s*(\d+)/i.exec(b.subarray(0, e).toString())[1]);
+		const m = JSON.parse(b.subarray(e + 4, e + 4 + n)); b = b.subarray(e + 4 + n);
+		if (m.method === 'textDocument/publishDiagnostics') last = m.params.diagnostics;
+	}
+	assert.ok(last, 'no diagnostics published');
+	return last;
+}
+function zy(text) {
+	const zyBin = process.env.ZY || path.join(path.dirname(process.argv[2]), 'zy');
+	const r = cp.spawnSync(zyBin, [], { input: text, timeout: 30000 * TIMEOUT_SCALE });
+	const line = String(r.stdout).split('\n')[0];
+	return line.replace(/^zc: line \d+: /, '');
+}
+const at = (text, needle, nth = 0) => { let o = -1; for (let k = 0; k <= nth; k++) o = text.indexOf(needle, o + 1); const before = text.slice(0, o); return { line: before.split('\n').length - 1, character: o - before.lastIndexOf('\n') - 1 }; };
+let checks = 0;
+function same(text, label) {
+	const d = diagnose(text).filter(x => x.severity === 1);
+	assert.ok(d.length >= 1, label + ': no error');
+	const fromZy = zy(text);
+	assert.ok(fromZy && d.some(x => x.message === fromZy), `${label}: editor and zy disagree: [${d.map(x => x.message)}] vs [${fromZy}]`);
+	checks++;
+	return d.find(x => x.message === fromZy);
+}
+// a borrow used after its owner is freed
+let text = 'include rt;\nfn main() {\n\tchar* t = rt.new(4); t[0] = 65;\n\tchar* r = t + 1;\n\trt.free(t);\n\treturn r[0];\n}\n';
+let d = same(text, 'freed owner');
+assert.match(d.message, /r borrows t, and t was freed/);
+assert.deepStrictEqual(d.range.start, at(text, 'r[0]'), 'the range is the conflicting use');
+assert.ok(d.relatedInformation && d.relatedInformation.length === 2, JSON.stringify(d));
+assert.strictEqual(d.relatedInformation[0].message, 'owner t was freed here');
+assert.deepStrictEqual(d.relatedInformation[0].location.range.start, at(text, 't);'));
+assert.strictEqual(d.relatedInformation[0].location.uri, uri);
+assert.strictEqual(d.relatedInformation[1].message, 'owner t is declared here');
+assert.deepStrictEqual(d.relatedInformation[1].location.range.start, at(text, 't ='));
+// the owner itself, given to a .d parameter
+text = 'include rt;\nfn take(.d p) { return p[0]; }\nfn main() { let x = rt.new(3); take(x); return x[0]; }\n';
+d = same(text, '.d parameter');
+assert.match(d.message, /x was given to take's \.d parameter/);
+assert.strictEqual(d.relatedInformation[0].message, 'owner x was given to a .d parameter here');
+assert.deepStrictEqual(d.relatedInformation[0].location.range.start, at(text, 'x)'));
+// a function called before its body, reported at the end of the unit at the use
+text = 'include rt;\nfn main() {\n\tchar* t = rt.new(8); t[0] = 32; t[1] = 0;\n\tlet r = skip(t); rt.free(t); rt.put_c(r[0]);\n\treturn 0;\n}\nchar* skip(char* s) { return s + 1; }\n';
+d = same(text, 'forward call');
+assert.match(d.message, /skip, defined after this call, returns a borrow/);
+assert.deepStrictEqual(d.range.start, at(text, 'r[0]'));
+assert.strictEqual(d.relatedInformation[0].message, 'owner t was freed here');
+// a borrows clause checked against its body
+text = 'include rt;\nchar* first(char* a, char* b) borrows a;\nchar* first(char* a, char* b) { return b; }\nfn main() { return 0; }\n';
+d = same(text, 'borrows clause');
+assert.match(d.message, /returns a borrow of b/);
+console.log(`ok   borrow diagnostics: ${checks} cases match zy, with ranges and related owner places`);
diff --git a/tests/drivers/ext_cache_test.js b/tests/drivers/ext_cache_test.js
index 93caf94..9bd3e3a 100644
--- a/tests/drivers/ext_cache_test.js
+++ b/tests/drivers/ext_cache_test.js
@@ -31,6 +31,8 @@ const stub = {
     EventEmitter: class { constructor() { this.event = () => ({ dispose() {} }); } fire() {} },
     Diagnostic: class { constructor(range, message, severity) { Object.assign(this, { range, message, severity }); } },
     Range: class { constructor(a, b, c, d) { Object.assign(this, { start: { line: a, character: b }, end: { line: c, character: d } }); } },
+    Location: class { constructor(uri, range) { Object.assign(this, { uri, range }); } },
+    DiagnosticRelatedInformation: class { constructor(location, message) { Object.assign(this, { location, message }); } },
     DiagnosticSeverity: { Error: 0, Warning: 1, Information: 2, Hint: 3 },
     SemanticTokensLegend: class { constructor(t, m) { this.tokenTypes = t; this.tokenModifiers = m; } },
     SemanticTokensBuilder: class { constructor() {} push() {} build() { return null; } },
@@ -177,6 +179,17 @@ const mainUri = 'file://' + main;
     const expiredList = await world.completion.provideCompletionItems(expiredDoc, { line: 3, character: 1 }, { isCancellationRequested: false });
     const expiredItem = expiredList && expiredList.items.find(c => c.label === 'used');
     check('completion maps consumed lifetimes to the editor strikethrough tag', expiredItem && expiredItem.tags?.[0] === stub.CompletionItemTag.Deprecated && /lifetime ended/.test(expiredItem.documentation?.value));
+    // a borrow error keeps the server's related information: where the owner ended and where it was declared
+    const borrowPath = path.join(root, 'borrow.zc');
+    const borrowDoc = doc(borrowPath, 'include rt;\nfn main() {\n\tchar* t = rt.new(4); t[0] = 65;\n\tchar* r = t + 1;\n\trt.free(t);\n\treturn r[0];\n}\n');
+    fs.writeFileSync(borrowPath, borrowDoc.text);
+    world.textDocuments.push(borrowDoc);
+    if (world.listeners.onDidOpenTextDocument) world.listeners.onDidOpenTextDocument(borrowDoc);
+    await until(() => world.sets.some(s => s.uri === 'file://' + borrowPath && s.list.length));
+    const borrowSet = world.sets.filter(s => s.uri === 'file://' + borrowPath).pop();
+    const borrowDiag = borrowSet && borrowSet.list.find(d => /r borrows t/.test(d.message));
+    const related = borrowDiag && borrowDiag.relatedInformation;
+    check('borrow diagnostics pass related information through to the editor', related && related.length === 2 && related[0] instanceof stub.DiagnosticRelatedInformation && related[0].message === 'owner t was freed here' && related[0].location.range.start.line === 4 && related[1].message === 'owner t is declared here', JSON.stringify(borrowSet && borrowSet.list));
     const actionDoc = doc(path.join(root, 'imports.zc'), 'fn main() { rt.put_n(7); }');
     const actions = await world.actions.provideCodeActions(actionDoc, new stub.Range(0, 15, 0, 15), {}, { isCancellationRequested: false });
     check('quick fixes reach the editor as workspace edits', actions.some(a => a.kind === 'quickfix' && a.edit.edits.some(e => e.newText === 'include rt;\n')));