4. Your first sequence

Open a second terminal — the first one is busy serving your step — and set it up:

$ cd ~/anvil-book
$ export PATH="$PWD/anvil-v0.9.0-x86_64-linux-musl:$PATH"
$ mkdir sequences

The file

Create sequences/first.yseq:

name: first

executors:
  - { name: bench, type: grpc, host: 127.0.0.1, port: 9201 }

main:
  - name: board/measure_rail
    type: numeric_limit
    module: board/measure_rail
    executor: bench
    limit: { comparison: GELE, low: 4.75, high: 5.25 }

It is YAML. Line by line:

• name names the sequence in reports.
• executors is the list of executors this sequence talks to. Each has a name you choose, a type — grpc for a process listening on a port, as your C# executor is — and where to find it.
• main is the list of steps to run. Chapter 6 adds setup and cleanup.
• Each step has a name, which is how the report shows it, and a type, which says how it is judged. numeric_limit judges a number against a limit; chapter 5 shows the others. They are TestStand’s step types.
• module is what the step calls — the name the executor publishes — and executor is who serves it, by the name you gave it above. Here the step is named after its module; two steps calling one module with different inputs would each get a name of their own.
• limit is the acceptance criterion, in TestStand’s terms: GELE passes when the measurement is greater than or equal to low and less than or equal to high.

Every step that calls an executor names it with executor:. Anvil has no executor of its own to fall back on, so a step without one is refused when the sequence loads, with a message that says what to add.

The extension can be .yseq or .yaml; Anvil reads both the same way.

Run it

$ anvil sequences/first.yseq
secuencia 'first' cargada (1 pasos en main, 0 subsecuencia(s) externa(s), 1 ejecutor(es))
connected to the step executors (bench)
1 paso(s) comprobados contra el catálogo de su ejecutor
=== first: pass ===
  [pass] board/measure_rail: 
$ echo $?
0

Two kinds of lines are mixed there.

The report is the part between === first: pass === and the step lines under it: the sequence passed, and so did its one step. It goes to standard output.

Everything else is diagnostics on the error stream: loading the file, connecting to bench, and — the line that matters — 1 paso(s) comprobados contra el catálogo de su ejecutor, “1 step checked against its executor’s catalog”. Before running anything, Anvil asked bench what it serves and checked that the sequence only asks for steps that exist. These messages are still in Spanish in 0.5.0 (#59).

The exit code is 0 because the sequence passed. Anything else — a fail, an error, a file that does not load — exits with 1.

To see only the report, send the diagnostics away:

$ anvil sequences/first.yseq 2>/dev/null
=== first: pass ===
  [pass] board/measure_rail: 

The rest of the book does that, unless the diagnostics are the point.

The console report does not show the measured value — 4.98 appears nowhere. The reports in chapter 10 carry it.

When a name is wrong

Make a typo on purpose. sequences/unknown.yseq asks for measure_rial:

name: unknown

executors:
  - { name: bench, type: grpc, host: 127.0.0.1, port: 9201 }

main:
  - name: board/measure_rial
    type: pass_fail
    module: board/measure_rial
    executor: bench

$ anvil sequences/unknown.yseq 2>&1 | tail -n 3
connected to the step executors (bench)
la secuencia no casa con lo que ofrecen los ejecutores (1 problema(s)):
  - step 'board/measure_rial': executor 'bench' does not serve it (it serves: board/measure_rail)

“The sequence does not match what the executors offer”: bench does not serve board/measure_rial, and the message lists what it does serve. Nothing ran. This check happens on every run, before the first step, so a misspelt step never gets as far as the bench.