dbg()

Output a message in the query response and return the message.

Signature

dbg()(message: T): T

Description

The dbg() method outputs message in the query response summary field and returns message. It includes a preview of the calling location.

The message template is:

info: <message>
at *<source>*:<line>:<column>
       |
<line> | dbg(<message>)
       |    ^^^^^^^^^^^
       |

where:

Field Description

<source>

Message source.
One of:

Source Description

query

The dbg() call occurred in the main query body.

udf:<function>

The dbg() call occurred in the user-defined function named <function>

<line>

Line number where dbg() is used.

<column>

Character offset in <line> where dbg() is used.

<message>

String-serialized message.

Parameters

Parameter Type Required Description

message

Any

Yes

Value to output to the query response.

Return value

Type Description

Any

Returns message.

Examples

  1. Output a composed value in the query response:

    Product.create({
  name: "debug1",
  quantity: dbg(1 + 2 + 3),
})
    info: 6
at *query*:3:16
  |
3 |   quantity: dbg(1 + 2 + 3),
  |                ^^^^^^^^^^^
  |

{
  id: "394873023799230528",
  coll: Product,
  ts: Time("2099-04-11T12:38:31.050Z"),
  name: "debug1",
  quantity: 6
}

  2. Output a Struct:

    Product.create(
  dbg({
    name: "debug2",
    quantity: 1 + 2 + 3,
  })
)
    info: { name: "debug2", quantity: 6 }
at *query*:2:6
  |
2 |     dbg({
  |  ______^
3 | |     name: "debug2",
4 | |     quantity: 1 + 2 + 3
5 | |   })
  | |____^
  |

{
  id: "394873104675897408",
  coll: Product,
  ts: Time("2099-04-11T12:39:48.180Z"),
  name: "debug2",
  quantity: 6
}

  3. Output a Document:

    dbg(
  Product.create({
    name: "debug3",
    quantity: 1 + 2 + 3,
  })
)
    info: { id: ID("394873211262599234"), coll: Product, ts: TransactionTime(), name: "debug3", quantity: 6 }
at *query*:1:4
  |
1 |   dbg(
  |  ____^
2 | |   Product.create({
3 | |     name: "debug3",
4 | |     quantity: 1 + 2 + 3,
5 | |   })
6 | | )
  | |_^
  |

{
  id: "394873211262599234",
  coll: Product,
  ts: Time("2099-04-11T12:41:29.835Z"),
  name: "debug3",
  quantity: 6
}

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