nx_gcode_emit_test.nx

nx_gcode_emit_test.nx -- end-to-end compose: hand-built unit square contour + Qidi X-Max 3 + Generic PLA -> emit full G-code file structure (preamble + layer + postamble) + verify the output contains expected G-code keywords. Closed-form invariants: (a) Emitter constructs OK; filament_xsect precomputed sane (positive Q14 value, ~39408 for 1.75mm filament). (b) Preamble emits successfully; output contains "M104 S215" (Generic PLA first-layer hotend) and "G28" (home all). (c) Per-layer emit produces non-zero output length growth. (d) Output contains "G1 X" (print moves). (e) Output contains "E" (extruder accumulation). (f) Postamble adds "M104 S0" (hotend off) and "M84" (motors off). (g) E_acc_q14 is non-zero after layer emit (filament was fed). (h) E_acc_q14 ~= perimeter_mm * E_per_mm; for a 1mm square perimeter = 4mm, E_per_mm ~= 0.0333 mm filament/mm move, so total E ~= 0.1332 mm ~= 2182 Q14 (±100 tolerance). (i) Final length is reasonable (200..10000 bytes for this case). expect_exit: 0 license_tier: ORIGINAL