Measurements

These assertions measure the whole subject. A STEP subject is measured from its BRep; a mesh, from its triangles. The engine picks the evidence from the subject, and the result's evidence names the source it used (brep or mesh).

toHaveBoundingBox

Asserts the axis-aligned bounds of the subject.

Signature

toHaveBoundingBox(first: Vec3 | BoundingBoxExpectation, second?: Vec3): GeoSpecAssertion

Two points are shorthand for { min: first, max: second }.

Payload

Each axis takes a number or a numeric expectation. Wire: { kind: 'boundingBox', expected }.

Admitted geometry

• STEP: the BRep bounds.
• Mesh and glTF/GLB: the bounds of the triangle vertices. On a mesh-buffer-v1 subject the claim charges three work units per triangle before it measures.

Refusal codes

The common refusals only. A failed claim carries GEOSPEC_BOUNDING_BOX_MISMATCH, or GEOSPEC_NEGATED_BOUNDING_BOX_MATCH under negation.

Examples

// passed: box, the 10 × 20 × 30 mm quick-start mesh
expectGeo(box).toHaveBoundingBox({ size: [10, 20, 30] });
// refused (GEOSPEC_EVIDENCE_UNSUPPORTED): tessellatedStep, a STEP box whose faces carry no surface
expectGeo(tessellatedStep).toHaveBoundingBox({ size: [10, 20, 30] });

expect_geo(box).to_have_bounding_box(size=[10, 20, 30])  # passed
expect_geo(tessellated_step).to_have_bounding_box(size=[10, 20, 30])  # refused

toHaveSurfaceArea

Asserts the total surface area of the subject.

Signature

toHaveSurfaceArea(expected: { value: number | NumericExpectation; tolerance?: number }): GeoSpecAssertion

Payload

Wire: { kind: 'surfaceArea', expected }.

Admitted geometry

• STEP: the BRep surface area.
• Mesh and glTF/GLB: the sum of the triangle areas. A mesh approximates curved faces, so its area differs from the BRep area of the same part.

Refusal codes

The common refusals only. A failed claim carries GEOSPEC_MEASUREMENT_MISMATCH.

Examples

// passed: box, the 10 × 20 × 30 mm quick-start mesh
expectGeo(box).toHaveSurfaceArea({ value: 2200 });
// refused (GEOSPEC_EVIDENCE_UNSUPPORTED): tessellatedStep, a STEP box whose faces carry no surface
expectGeo(tessellatedStep).toHaveSurfaceArea({ value: 2200 });

expect_geo(box).to_have_surface_area(value=2200)  # passed
expect_geo(tessellated_step).to_have_surface_area(value=2200)  # refused

toHaveVolume

Asserts the enclosed volume of the subject.

Signature

toHaveVolume(expected: { value: number | NumericExpectation; tolerance?: number }): GeoSpecAssertion

Payload

Wire: { kind: 'volume', expected }.

Admitted geometry

• STEP: the BRep volume.
• Mesh and glTF/GLB: the absolute signed volume of the triangles. An open mesh still yields a number, so pair the claim with toBeWatertight.

Refusal codes

The common refusals only. A failed claim carries GEOSPEC_MEASUREMENT_MISMATCH.

Examples

// passed: box, the 10 × 20 × 30 mm quick-start mesh
expectGeo(box).toHaveVolume({ value: 6000, tolerance: 0.5 });
// refused (GEOSPEC_EVIDENCE_UNSUPPORTED): tessellatedStep, a STEP box whose faces carry no surface
expectGeo(tessellatedStep).toHaveVolume({ value: 6000 });

expect_geo(box).to_have_volume(value=6000, tolerance=0.5)  # passed
expect_geo(tessellated_step).to_have_volume(value=6000)  # refused

toHaveMass

Asserts the mass of the subject, derived as volume × density.

Signature

toHaveMass(expected: { value: number | NumericExpectation; density?: number; tolerance?: number }): GeoSpecAssertion

Payload

The mass unit follows density: grams per mm³ gives grams. Wire: { kind: 'mass', expected }.

Admitted geometry

• The volume comes from the same evidence as toHaveVolume.
• No admitted subject carries a material mass, so a claim without density refuses on every subject.

Refusal codes

• GEOSPEC_EVIDENCE_UNSUPPORTED: the claim declares no density.

A failed claim carries GEOSPEC_MEASUREMENT_MISMATCH.

Examples

// passed: box, the 10 × 20 × 30 mm quick-start mesh, in aluminium at 0.0027 g/mm³
expectGeo(box).toHaveMass({ value: 16.2, density: 0.0027 });
// refused (GEOSPEC_EVIDENCE_UNSUPPORTED): the same box with no density declared
expectGeo(box).toHaveMass({ value: 16.2 });

expect_geo(box).to_have_mass(value=16.2, density=0.0027)  # passed
expect_geo(box).to_have_mass(value=16.2)  # refused

toHaveCenterOfMass

Asserts the centre of mass of the subject, assuming uniform density.

Signature

toHaveCenterOfMass(expected: { point: Vec3 | { x?: number; y?: number; z?: number }; tolerance?: number }): GeoSpecAssertion

Payload

Each declared axis is compared on its own. Wire: { kind: 'centerOfMass', expected }.

Admitted geometry

• STEP: the BRep centre of mass of a solid with nonzero volume.
• Mesh and glTF/GLB: the centroid of the enclosed volume. An open mesh still yields a point, so pair the claim with toBeWatertight.

Refusal codes

• GEOSPEC_EVIDENCE_UNSUPPORTED: the subject has no centre of mass, such as a STEP shape with zero volume.

A failed claim carries GEOSPEC_MEASUREMENT_MISMATCH.

Examples

// passed: box, the 10 × 20 × 30 mm quick-start mesh
expectGeo(box).toHaveCenterOfMass({ point: [5, 10, 15] });
// refused (GEOSPEC_EVIDENCE_UNSUPPORTED): tessellatedStep, a STEP box whose faces carry no surface
expectGeo(tessellatedStep).toHaveCenterOfMass({ point: [5, 10, 15] });

expect_geo(box).to_have_center_of_mass(point=[5, 10, 15])  # passed
expect_geo(tessellated_step).to_have_center_of_mass(point=[5, 10, 15])  # refused