feat: convert xsd:date and xsd:dateTime literals to JavaScript Date objects #123

Copilot · 2026-01-02T21:10:24Z

Original prompt

This section details on the original issue you should resolve

<issue_title>feat: improved literal handling</issue_title>
<issue_description>Rather than all literals being converted to strings it would be nice to have numeric types go to numbers, dateTimes go to Dates and so forth.

You should be able to largely use https://www.npmjs.com/package/rdf-literal or re-use https://github.com/LDflex/LDflex/blob/3379cb7059dccdfb41de804a2e0db338e974cc3a/src/valueUtils.js to achieve this.

Edit I've noticed that you have this in some cases, added support for dates would be excellent</issue_description>

Comments on the Issue (you are @copilot in this section)

Fixes feat: improved literal handling #26

💬 We'd love your input! Share your thoughts on Copilot coding agent in our 2 minute survey.

…e to JavaScript Date objects Co-authored-by: jeswr <63333554+jeswr@users.noreply.github.com>

Co-authored-by: jeswr <63333554+jeswr@users.noreply.github.com>

elf-pavlik · 2026-01-02T23:03:39Z

Eventually it might be better to use https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal/Instant

There are some existing polyfills, maybe it's better to use them rather than making a breaking change once Temporal becomes more broadly available? https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Temporal#see_also

jeswr · 2026-01-03T13:17:44Z

I'd be inclined to stick with Date until Temporal.Instant is more widely adopted.

Copilot

Pull request overview

This PR enhances literal handling by adding automatic conversion of xsd:date and xsd:dateTime RDF literals to JavaScript Date objects, similar to existing numeric and boolean conversions.

Key Changes

Reading: xsd:date and xsd:dateTime literals are automatically parsed into Date objects instead of remaining as strings
Writing: Date objects can be set on date fields and are serialized appropriately (date-only format for xsd:date, full ISO 8601 for xsd:dateTime)
Types: Updated LiteralLike and RawValue type definitions to include Date, enabling proper TypeScript type checking

Reviewed changes

Copilot reviewed 8 out of 8 changed files in this pull request and generated 5 comments.

Show a summary per file

File	Description
`packages/jsonld-dataset-proxy/src/util/nodeToJsonldRepresentation.ts`	Adds Date object creation for xsd:date and xsd:dateTime literals during reading
`packages/jsonld-dataset-proxy/src/util/getNodeFromRaw.ts`	Implements Date serialization logic with format selection based on datatype (date-only vs full ISO)
`packages/jsonld-dataset-proxy/src/types.ts`	Extends LiteralLike type to include Date
`packages/jsonld-dataset-proxy/src/util/RawObject.ts`	Extends RawValue type to include Date
`packages/jsonld-dataset-proxy/src/subjectProxy/getValueForKey.ts`	Updates return type signature to include Date
`packages/jsonld-dataset-proxy/test/patientExampleData.ts`	Updates PatientShape type to accept Date for birthdate field
`packages/jsonld-dataset-proxy/test/nodeToJsonRepresentation.test.ts`	Adds comprehensive tests for date/dateTime parsing including timezone handling
`packages/jsonld-dataset-proxy/test/jsonldDatasetProxy.test.ts`	Updates test expectations to validate Date objects and fixes date format in test data

💡 Add Copilot custom instructions for smarter, more guided reviews. Learn how to get started.

packages/jsonld-dataset-proxy/test/jsonldDatasetProxy.test.ts

Copilot · 2026-01-03T13:20:01Z

packages/jsonld-dataset-proxy/src/util/getNodeFromRaw.ts

+    } else {
+      // Use full ISO format for xsd:dateTime and other date-related types
+      return literal(value.toISOString(), datatype);


The else branch at line 42-44 converts any Date object to ISO string format when the datatype is not xsd:date, even for non-date-related datatypes. This could lead to unexpected behavior if a Date object is accidentally passed for a field with a different datatype (e.g., xsd:string). Consider restricting Date object handling to only xsd:date and xsd:dateTime datatypes, and either throw an error or return undefined for other datatypes.

Suggested change

} else {

// Use full ISO format for xsd:dateTime and other date-related types

return literal(value.toISOString(), datatype);

} else if (datatype === "http://www.w3.org/2001/XMLSchema#dateTime") {

// Use full ISO format for xsd:dateTime

return literal(value.toISOString(), datatype);

} else {

// For non-date-related datatypes, do not coerce Date values

return undefined;

Applied this suggestion in 587aa3e. Date objects are now only accepted for xsd:date and xsd:dateTime datatypes, returning undefined for other datatypes.

Copilot · 2026-01-03T13:20:01Z

packages/jsonld-dataset-proxy/src/util/nodeToJsonldRepresentation.ts

    case "http://www.w3.org/2001/XMLSchema#dateTime":
+      return new Date(literal.value);


The Date constructor may create an invalid Date object if the literal value is malformed. Consider adding validation to check if the date is valid using isNaN(date.getTime()) and returning the original string value if parsing fails, maintaining backward compatibility with invalid date strings.

Suggested change

case "http://www.w3.org/2001/XMLSchema#dateTime":

return new Date(literal.value);

case "http://www.w3.org/2001/XMLSchema#dateTime": {

const date = new Date(literal.value);

return isNaN(date.getTime()) ? literal.value : date;

}

Applied this suggestion in 587aa3e. Invalid dates now return the original string value.

packages/jsonld-dataset-proxy/test/nodeToJsonRepresentation.test.ts

Copilot · 2026-01-03T13:20:02Z

packages/jsonld-dataset-proxy/test/nodeToJsonRepresentation.test.ts

+    ).toBe("P1Y2M3D");
+  });
+
  it("throws an error when it encoutners a quad that is not a Liter, NamedNode, or BlankNode", () => {


Spelling error: "encoutners" should be "encounters" and "Liter" should be "Literal".

Suggested change

it("throws an error when it encoutners a quad that is not a Liter, NamedNode, or BlankNode", () => {

it("throws an error when it encounters a quad that is not a Literal, NamedNode, or BlankNode", () => {

Fixed in 587aa3e.

jeswr · 2026-01-03T13:23:10Z

@copilot apply changes based on the comments in this thread

- Validate Date parsing and return original string for invalid dates - Restrict Date coercion to only xsd:date and xsd:dateTime datatypes - Add tests for invalid date strings - Add timezone edge case test for xsd:date serialization - Fix spelling errors in test description Co-authored-by: jeswr <63333554+jeswr@users.noreply.github.com>

Copilot · 2026-01-03T13:30:29Z

@copilot apply changes based on the comments in this thread

Applied all the requested changes in commit 587aa3e:

Added validation for invalid Date parsing (returns original string if invalid)
Restricted Date coercion to only xsd:date and xsd:dateTime datatypes
Added tests for invalid date strings
Added timezone edge case test
Fixed spelling errors in test description

jeswr · 2026-01-03T13:45:27Z

@copilot please revert the support for invalid dates

Per reviewer request, reverted the invalid date validation that returned the original string for malformed dates. Invalid dates will now return an Invalid Date object, consistent with standard JavaScript Date behavior. Co-authored-by: jeswr <63333554+jeswr@users.noreply.github.com>

Copilot · 2026-01-03T13:49:58Z

@copilot please revert the support for invalid dates

Reverted in 91e6d86. Invalid dates will now return an Invalid Date object consistent with standard JavaScript Date behavior.

packages/jsonld-dataset-proxy/test/patientExampleData.ts

Initial plan

acd9869

Copilot AI assigned Copilot and jeswr Jan 2, 2026

Copilot started work on behalf of jeswr January 2, 2026 21:10 View session

Copilot AI and others added 2 commits January 2, 2026 21:23

feat: improve literal handling by converting xsd:date and xsd:dateTim…

5c2a2d8

…e to JavaScript Date objects Co-authored-by: jeswr <63333554+jeswr@users.noreply.github.com>

fix: format xsd:date as date-only and prevent Date as @id

3199714

Co-authored-by: jeswr <63333554+jeswr@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Improve handling of numeric and date literals~~ feat: convert xsd:date and xsd:dateTime literals to JavaScript Date objects Jan 2, 2026

Copilot finished work on behalf of jeswr January 2, 2026 21:29

Copilot AI requested a review from jeswr January 2, 2026 21:29

jeswr marked this pull request as ready for review January 3, 2026 13:16

Copilot AI review requested due to automatic review settings January 3, 2026 13:16

Copilot started reviewing on behalf of jeswr January 3, 2026 13:17 View session

Copilot AI reviewed Jan 3, 2026

View reviewed changes

Copilot started work on behalf of jeswr January 3, 2026 13:23 View session

Copilot finished work on behalf of jeswr January 3, 2026 13:31

Copilot started work on behalf of jeswr January 3, 2026 13:46 View session

Copilot finished work on behalf of jeswr January 3, 2026 13:50

jeswr reviewed Jan 3, 2026

View reviewed changes

packages/jsonld-dataset-proxy/test/patientExampleData.ts Outdated Show resolved Hide resolved

Update packages/jsonld-dataset-proxy/test/patientExampleData.ts

740902c

jeswr requested a review from jaxoncreed January 3, 2026 14:04

		case "http://www.w3.org/2001/XMLSchema#dateTime":
		return new Date(literal.value);

-    case "http://www.w3.org/2001/XMLSchema#dateTime":
-      return new Date(literal.value);
+    case "http://www.w3.org/2001/XMLSchema#dateTime": {
+      const date = new Date(literal.value);
+      return isNaN(date.getTime()) ? literal.value : date;
+    }

	it("throws an error when it encoutners a quad that is not a Liter, NamedNode, or BlankNode", () => {
	it("throws an error when it encounters a quad that is not a Literal, NamedNode, or BlankNode", () => {

feat: convert xsd:date and xsd:dateTime literals to JavaScript Date objects #123

Are you sure you want to change the base?

feat: convert xsd:date and xsd:dateTime literals to JavaScript Date objects #123

Uh oh!

Conversation

Copilot AI commented Jan 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Comments on the Issue (you are @copilot in this section)

Uh oh!

elf-pavlik commented Jan 2, 2026

Uh oh!

jeswr commented Jan 3, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Key Changes

Reviewed changes

Uh oh!

Uh oh!

Copilot AI Jan 3, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Jan 3, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Jan 3, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Jan 3, 2026

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Copilot AI Jan 3, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Jan 3, 2026

Choose a reason for hiding this comment

Uh oh!

jeswr commented Jan 3, 2026

Uh oh!

Copilot AI commented Jan 3, 2026

Uh oh!

jeswr commented Jan 3, 2026

Uh oh!

Copilot AI commented Jan 3, 2026

Uh oh!

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Copilot AI commented Jan 2, 2026 •

edited

Loading