--- id: post/stefanmaron-com/https-stefanmaron-com-posts-al-runner-autonomous-agent-weekend--030ecee688 type: post title: "AL Runner: A Weekend of Autonomous Agents, a Windows Cross-Check, and 59% of Microsoft's Tests Passing" summary: Stefan Maron describes a weekend of autonomous agent loops on AL Runner, shipped as v2.11.0, and its companion AL language test suite, which grew by 832 tests. A new nightly Windows workflow found a missing TestPermissions property in about 100 test codeunits and 8 behavioral differences between BC on Linux and real BC. A full run of Microsoft's BaseApp tests now passes 59.2%, and a hang was traced to a dropped report MaxIteration property. tier: community language: en tags: - al runner - autonomous agents - testing framework - linux vs windows - test coverage - platform differences system: development review: state: reviewed by: opus at: "2026-10-07T23:47:00.607Z" flags: [] generated: at: "2026-10-07T22:42:12.892Z" pipeline: 0.2.0 prompts: extract-post: 1 input_hash: 8567239c1b6771e66ee7f073c30e826d3ea4e6668eee7621025d7ea7ee229135 evidence: - kind: blog url: https://stefanmaron.com/posts/al-runner-autonomous-agent-weekend/ title: "AL Runner: A Weekend of Autonomous Agents, a Windows Cross-Check, and 59% of Microsoft's Tests Passing" date: "2026-09-08" commit: null t: null quote: null - kind: blog url: https://stefanmaron.com/posts/al-runner-autonomous-agent-weekend/ title: "AL Runner: A Weekend of Autonomous Agents, a Windows Cross-Check, and 59% of Microsoft's Tests Passing" date: "2026-09-08" commit: null t: null quote: Every one of those tests pins its answer against a real BC service tier - kind: blog url: https://stefanmaron.com/posts/al-runner-autonomous-agent-weekend/ title: "AL Runner: A Weekend of Autonomous Agents, a Windows Cross-Check, and 59% of Microsoft's Tests Passing" date: "2026-09-08" commit: null t: null quote: 59.2% is coverage of everything AL Runner can discover, not coverage of what Microsoft actually runs day to day. links: learn: [] objects: [] features: [] topics: [] localizations: [] videos: [] posts: [] guidelines: [] post_id: https://stefanmaron.com/posts/al-runner-autonomous-agent-weekend/ source_id: stefanmaron-com source_name: Stefan Maron url: https://stefanmaron.com/posts/al-runner-autonomous-agent-weekend/ published_at: "2026-09-08T05:33:56.000Z" author: Stefan Maron full_text: false words: 1359 quotes: - text: Every one of those tests pins its answer against a real BC service tier why_it_matters: Shows the rigor of the test suite - tests validate against actual running BC instances, not mocks, ensuring reliability. - text: 59.2% is coverage of everything AL Runner can discover, not coverage of what Microsoft actually runs day to day. why_it_matters: Clarifies what test coverage percentages mean and that Microsoft itself disables over 40% of available tests, providing context for improvement targets. code_objects_mentioned: - other SymbolReference.json systems: - development - platform versions_mentioned: - v2.11.0 preview: embeddable: true frame_url: null image: null image_alt: null image_w: null image_h: null site_name: Stefan Maron favicon: https://stefanmaron.com/icons/favicon-32x32.png probed_at: "2026-10-07T11:50:07.945Z" --- # AL Runner: A Weekend of Autonomous Agents, a Windows Cross-Check, and 59% of Microsoft's Tests Passing [Read the post](https://stefanmaron.com/posts/al-runner-autonomous-agent-weekend/) · Stefan Maron (Stefan Maron, MVP) · 2026-09-08 · 1359 words · tier community · reviewed (checked by Opus) > Stefan Maron describes a weekend of autonomous agent loops on AL Runner, shipped as v2.11.0, and its companion AL language test suite, which grew by 832 tests. A new nightly Windows workflow found a missing TestPermissions property in about 100 test codeunits and 8 behavioral differences between BC on Linux and real BC. A full run of Microsoft's BaseApp tests now passes 59.2%, and a hang was traced to a dropped report MaxIteration property. ## Key points - AL Runner shipped v2.11.0 after 351 merged PRs. The companion test suite went from 2,346 to 3,178 tests in five days. - A manual check against a SaaS sandbox, followed by a nightly Windows container workflow, exposed tests passing on Linux CI but failing on real BC. Most failures came from a missing TestPermissions property. - Eight Linux-versus-Windows differences were filed, including lost SingleInstance codeunit state and IsolatedStorage encryption doing nothing under Linux. Five are closed. - AL Runner passes 23,985 of 40,530 Microsoft BaseApp tests (59.2%). Microsoft itself disables 16,141 of them, so a figure adjusted to the tests Microsoft actually runs is still being worked out. - Rebuilding report metadata from SymbolReference.json dropped MaxIteration, so one report dataitem looped 101,001 times. The bug was fixed at 5 call sites. ## Quotes - "Every one of those tests pins its answer against a real BC service tier" (Shows the rigor of the test suite - tests validate against actual running BC instances, not mocks, ensuring reliability.) - "59.2% is coverage of everything AL Runner can discover, not coverage of what Microsoft actually runs day to day." (Clarifies what test coverage percentages mean and that Microsoft itself disables over 40% of available tests, providing context for improvement targets.) ## AL objects mentioned As named in the post. A name that matches one object page by exact type and name links to it; the others stay as named. - other "SymbolReference.json" ## Context - Features: AL Runner testing framework, Autonomous agent loops for implementation and review, Windows and Linux cross-platform testing, Nightly automated test workflows, Permission-based test validation, Report metadata reconstruction, TestPermissions property handling, Microsoft base-app test execution - Versions: v2.11.0 Source: Stefan Maron, community blog. Summary, key points and quotes are derived (CONTENT-NOTICE.md); read the original for the full text.