PICT Pairwise Testing with CoverTable

Syntax highlighting, live diagnostics, and covering-array generation for Microsoft PICT model files, powered by the CoverTable engine — no external binary required.

Features

• Syntax highlighting for .pict files: parameters, values, weights (N), negatives ~, aliases a|b, parameter references <Name>, sub-models { A, B } @ N, the constraint language (IF/THEN/ELSE, AND/OR/NOT, IN/LIKE, [Field] refs, sets, strings, arithmetic), and formula columns (a value starting with =, with its function names, strings, and [Column] references highlighted).

• Diagnostics: unknown references, malformed constraints, and other parse errors are surfaced inline with line numbers, as you type. A [Field] reference that names no existing parameter — whether in a constraint or a formula column — is flagged right on that […] token.

• Generate Covering Array: run the model and open the result as a TSV/CSV table (always with a header row). You are prompted for the output file name, pre-filled with the default extension <model>.pict.tsv — with the base name pre-selected, so it is easy to change to anything you like. The format follows the extension you give: .csv → CSV, anything else → TSV. The file is written next to the model, overwriting any existing file with that name, and opened. Command: PICT: Generate Covering Array (also on the editor context menu).

• Progress & cancel: generation runs in time slices with a determinate progress notification (<rows> rows · <pct>% · ~<n>s left) that stays responsive and can be cancelled mid-run. On completion you get a summary (row count, order, elapsed time) and a warning if any pairs were left uncovered by the constraints.

• Optimize (off by default): an optional simulated-annealing post-process that shrinks the array further — same coverage, fewer rows. It is disabled by default; to use it, turn on pict.optimize.enable in settings (see below). It is anytime — cancel to keep the best result found so far — but it ignores weights (it rewrites cell values freely), so leave it off if you rely on a weighted value distribution.

• Formula (computed) columns: a parameter line whose value begins with = is not a combinatorial factor but a spreadsheet formula emitted on every output row. Any [ColumnName] reference inside it is rewritten to the cell that column occupies on that row — the column letter comes from the column's position in the output header (1st = A, 2nd = B, …; formula columns count too) and the row number is the 1-based data-row index. For example, with columns Type, Size, …:

  Type: Single, Span
  Size: 10, 100, 1000
  AI:   =AI("summarize this config", [Size])
  

  emits an AI column of =AI("summarize this config", B1), =AI("summarize this config", B2), … — ready to evaluate when opened in a spreadsheet grid (e.g. GridSheet). Unknown […] names are flagged as diagnostics. The result always carries a header row, so a grid that treats row 1 as labels places the first data row at A1 and these references line up with the data.

• Status-bar footer: while a .pict file is active, the bottom bar shows Strength · Criterion · Sorter · Case · ▷ Generate. Click any option to change it (persisted to settings); click Generate to run.

Settings

The status-bar footer edits pict.strength, pict.criterion, pict.sorter, and pict.caseSensitive directly, so it stays in sync with these settings. The output format follows the file name: .csv → CSV, anything else → TSV.

Per-file { ... } @ N sub-models still override pict.strength for their factors.

Development

pnpm install          # or npm install
pnpm run compile      # bundle once to dist/extension.js
pnpm run watch        # rebuild on change

Then press F5 in VS Code to launch an Extension Development Host.

The extension imports the engine by package name — covertable and covertable/pict — resolved to the in-repo source via tsconfig.json paths (the same convention docs/ uses). esbuild honours those paths, so the engine is bundled straight from source and stays in lock-step with the library shipped in this repository. No build of typescript/ is required first.