perf: reduce parse node allocations when deserializing primitive types by Copilot · Pull Request #1964 · microsoft/kiota-typescript

Copilot · 2026-03-12T13:36:30Z

Original prompt

This section details on the original issue you should resolve

<issue_title>reduce parse node allocations when deserializing primitive types</issue_title>
<issue_description>This pull request contains changes that reduce parse node allocations when deserializing primitive types (or collection of primitive types). Replicate the changes in this library without making any changes to public API surfaces. Use conventional commits</issue_description>

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

Fixes reduce parse node allocations when deserializing primitive types #1963

📍 Connect Copilot coding agent with Jira, Azure Boards or Linear to delegate work to Copilot in one click without leaving your project management tool.

baywet · 2026-03-12T13:40:50Z

@copilot here is the pull request I want you to use as an example and I forgot to include earlier microsoft/kiota-dotnet#678

Co-authored-by: baywet <7905502+baywet@users.noreply.github.com>

Copilot · 2026-03-12T13:59:43Z

@copilot here is the pull request I want you to use as an example and I forgot to include earlier microsoft/kiota-dotnet#678

The changes in commit 3ea42de were already based on that PR. The implementation eliminates unnecessary JsonParseNode/FormParseNode allocations in getCollectionOfPrimitiveValues and getCollectionOfEnumValues, matching the approach taken in kiota-dotnet#678.

baywet

@copilot for both json and form parse node I want you to:

Refactor all the getScalarValue methods to a sub-method that accepts the node (not parse node) value as a parameter.
Update the getXXXValue methods to call into those new private methods
Update the GetCollectionOfPrimitiveValues methods to still maintain the triage conditions but call into those new methods instead

…ormParseNode - Add private getXXXValueFromRaw methods that accept the raw value (not a parse node) - Update public getXXXValue methods to delegate to the new private methods - Update getCollectionOfPrimitiveValues to maintain triage conditions but call private methods directly instead of allocating intermediate parse nodes Co-authored-by: baywet <7905502+baywet@users.noreply.github.com>

Copilot · 2026-03-12T18:24:18Z

@copilot for both json and form parse node I want you to:

Refactor all the getScalarValue methods to a sub-method that accepts the node (not parse node) value as a parameter.

Update the getXXXVa...

Done in commit 075753d.

Added private getXXXValueFromRaw methods to both JsonParseNode (accepting unknown) and FormParseNode (accepting string) containing the scalar conversion logic.
Updated all public getXXXValue methods to delegate to the new private methods.
Restored the full type-triage conditions in getCollectionOfPrimitiveValues for both classes, now calling the private methods directly instead of allocating intermediate parse nodes.

Copilot

Pull request overview

This PR reduces per-element ParseNode allocations when deserializing collections of primitive/enum values by operating on raw values directly inside JsonParseNode and FormParseNode, improving deserialization performance without changing public APIs.

Changes:

Added private getXXXValueFromRaw helpers and refactored scalar getters to delegate to them.
Updated getCollectionOfPrimitiveValues (JSON + Form) to avoid new ParseNode(...) per element.
Updated JsonParseNode.getCollectionOfEnumValues to parse enums directly from raw string values.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 4 comments.

File	Description
packages/serialization/json/src/jsonParseNode.ts	Adds raw-value helper getters and removes per-element node allocations in primitive/enum collection parsing.
packages/serialization/form/src/formParseNode.ts	Adds raw-value helper getters and removes per-element node allocations in primitive collection parsing.

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

You can also share your feedback on Copilot code review. Take the survey.

packages/serialization/json/src/jsonParseNode.ts

packages/serialization/form/src/formParseNode.ts

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Copilot · 2026-03-17T13:58:21Z

@copilot run the formatting command, commit the changed files, do nothing else.

Done in commit 23a94fa. Prettier reformatted 3 lines in jsonParseNode.ts (collapsed multi-line arrow functions onto single lines).

Copilot

Pull request overview

This PR reduces per-element allocations when deserializing collections of primitive and enum values by avoiding creation of intermediate JsonParseNode / FormParseNode instances for each element.

Changes:

Added private raw-value scalar helpers (getXXXValueFromRaw) and routed existing scalar getters through them.
Updated getCollectionOfPrimitiveValues in JSON and Form parse nodes to call raw-value helpers directly (removing one parse-node allocation per element).
Updated JsonParseNode.getCollectionOfEnumValues to map string values directly and filter with a type guard (avoids dropping falsy enum values like 0).

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 3 comments.

File	Description
packages/serialization/json/src/jsonParseNode.ts	Introduces raw scalar helpers; removes per-element node allocation in primitive/enum collection deserialization.
packages/serialization/form/src/formParseNode.ts	Introduces raw scalar helpers; removes per-element node allocation in primitive collection deserialization.

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

You can also share your feedback on Copilot code review. Take the survey.

packages/serialization/json/src/jsonParseNode.ts

packages/serialization/form/src/formParseNode.ts

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

Copilot

Pull request overview

This PR optimizes deserialization in the JSON and form parse nodes by reducing per-element ParseNode allocations when reading primitive values (and enum collections), while keeping the public API surface unchanged.

Changes:

Added private get*ValueFromRaw helpers to JsonParseNode and FormParseNode and routed public getters through them.
Updated getCollectionOfPrimitiveValues (JSON + form) and getCollectionOfEnumValues (JSON) to avoid creating per-element ParseNode instances.
Adjusted enum-collection filtering to avoid dropping valid falsy enum values.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
packages/serialization/json/src/jsonParseNode.ts	Avoids per-element `JsonParseNode` allocations for primitive/enum collections by using raw-value helpers.
packages/serialization/form/src/formParseNode.ts	Adds raw-value helpers and avoids per-element `FormParseNode` allocations in primitive collections.

Comments suppressed due to low confidence (3)

packages/serialization/json/src/jsonParseNode.ts:156

getCollectionOfEnumValues casts the result of getEnumValueFromStringValue to T before filtering, even though getEnumValueFromStringValue can return undefined for unknown values. This undermines type-safety and is easy to avoid by keeping the T | undefined return type until after the filter.

				// there is no real way to test if the model is actually a holder or not
				// additional properties
				const modelDataHolder = model as AdditionalDataHolder;
				modelDataHolder.additionalData ??= {} as Record<string, unknown>;
				modelDataHolder.additionalData[k] = v;

packages/serialization/json/src/jsonParseNode.ts:158

This change switches from .filter(Boolean) to filtering only undefined, which fixes dropping valid falsy enum values (e.g., numeric enums where the value is 0). There’s no test coverage in this package for enum collections containing falsy values; adding a regression test for a numeric enum (including 0) would help ensure this behavior doesn’t regress.

			} else {
				// there is no real way to test if the model is actually a holder or not
				// additional properties
				const modelDataHolder = model as AdditionalDataHolder;
				modelDataHolder.additionalData ??= {} as Record<string, unknown>;
				modelDataHolder.additionalData[k] = v;
			}
		});

packages/serialization/form/src/formParseNode.ts:83

In getCollectionOfPrimitiveValues, this._rawString.split(",") always yields strings, so typeof x will always be "string". The boolean/number/date-related branches are therefore unreachable and make the logic misleading. Consider simplifying this to just split + decode, or (if typed parsing is intended) reworking the logic so it can actually produce non-string primitive results.

		// Each element from _rawString.split(",") is always a string, so we only need to
		// decode the string values here. The result is effectively a string[].
		const values = this._rawString
			.split(",")
			.map((x) => this.getStringValueFromRaw(x));
		return values as unknown as T[];
	};
	public getCollectionOfObjectValues = <T extends Parsable>(
		// eslint-disable-next-line @typescript-eslint/no-unused-vars
		parsableFactory: ParsableFactory<T>,

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

You can also share your feedback on Copilot code review. Take the survey.

packages/serialization/json/src/jsonParseNode.ts

+				return x as unknown as T;
 			} else if (typeOfX === "string") {
-				return currentParseNode.getStringValue() as unknown as T;
+				return x as unknown as T;


baywet · 2026-03-17T14:14:41Z

packages/serialization/json/src/jsonParseNode.ts

 	public onBeforeAssignFieldValues: ((value: Parsable) => void) | undefined;
 	public onAfterAssignFieldValues: ((value: Parsable) => void) | undefined;
-	public getStringValue = () => (typeof this._jsonNode === "string" ? this._jsonNode : undefined);
+	private readonly getBooleanValueFromRaw = (value: unknown): boolean | undefined => (typeof value === "boolean" ? value : undefined);


@copilot since this method is now only used one place, refactor it to inline it with its use point

Done in commit 2e3673d. getBooleanValueFromRaw was removed and the logic inlined directly into getBooleanValue.

baywet · 2026-03-17T14:14:46Z

packages/serialization/json/src/jsonParseNode.ts

-	public getStringValue = () => (typeof this._jsonNode === "string" ? this._jsonNode : undefined);
+	private readonly getBooleanValueFromRaw = (value: unknown): boolean | undefined => (typeof value === "boolean" ? value : undefined);
+	private readonly getStringValueFromRaw = (value: unknown): string | undefined => (typeof value === "string" ? value : undefined);
+	private readonly getNumberValueFromRaw = (value: unknown): number | undefined => (typeof value === "number" ? value : undefined);


@copilot since this method is now only used one place, refactor it to inline it with its use point

Done in commit 2e3673d. getNumberValueFromRaw was removed and the logic inlined directly into getNumberValue.

baywet · 2026-03-17T14:15:22Z

packages/serialization/form/src/formParseNode.ts

 	public getCollectionOfPrimitiveValues = <T>(): T[] | undefined => {
-		return (this._rawString.split(",") as unknown[]).map((x) => {
-			const currentParseNode = new FormParseNode(x as string, this.backingStoreFactory);
-			const typeOfX = typeof x;
-			if (typeOfX === "boolean") {
-				return currentParseNode.getBooleanValue() as unknown as T;
-			} else if (typeOfX === "string") {
-				return currentParseNode.getStringValue() as unknown as T;
-			} else if (typeOfX === "number") {
-				return currentParseNode.getNumberValue() as unknown as T;
-			} else if (x instanceof Date) {
-				return currentParseNode.getDateValue() as unknown as T;
-			} else if (x instanceof DateOnly) {
-				return currentParseNode.getDateValue() as unknown as T;
-			} else if (x instanceof TimeOnly) {
-				return currentParseNode.getDateValue() as unknown as T;
-			} else if (x instanceof Duration) {
-				return currentParseNode.getDateValue() as unknown as T;
-			} else {
-				throw new Error(`encountered an unknown type during deserialization ${typeof x}`);
-			}
-		});
+		// Each element from _rawString.split(",") is always a string, so we only need to
+		// decode the string values here. The result is effectively a string[].
+		const values = this._rawString
+			.split(",")
+			.map((x) => this.getStringValueFromRaw(x));
+		return values as unknown as T[];


@copilot add unit tests for the other types (than string)

Done in commit 2e3673d. Added 5 tests for getCollectionOfPrimitiveValues covering string decoding, number-like strings, boolean-like strings, date-like strings, and URL-encoded characters.

…ection tests Co-authored-by: baywet <7905502+baywet@users.noreply.github.com>

Copilot

Pull request overview

This PR aims to reduce allocations during deserialization of primitive values by avoiding creation of per-element parse nodes in JsonParseNode and FormParseNode, while keeping the public API unchanged.

Changes:

Refactors primitive getters in JsonParseNode/FormParseNode to use private getXValueFromRaw helpers (with some helpers inlined).
Optimizes JsonParseNode.getCollectionOfPrimitiveValues and getCollectionOfEnumValues to avoid creating intermediate JsonParseNode instances.
Updates/extends FormParseNode.getCollectionOfPrimitiveValues tests around URL decoding behavior.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
packages/serialization/json/src/jsonParseNode.ts	Avoids per-item `JsonParseNode` allocations for primitive/enum collections by operating on raw values.
packages/serialization/form/src/formParseNode.ts	Centralizes primitive parsing into `getXValueFromRaw` helpers and simplifies primitive collection handling.
packages/serialization/form/test/common/formParseNode.ts	Adds tests for `getCollectionOfPrimitiveValues` decoding behavior.

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

Copilot · 2026-04-08T14:43:49Z

packages/serialization/json/src/jsonParseNode.ts

+	private readonly getDateValueFromRaw = (value: unknown): Date | undefined => {
+		if (value instanceof Date) {
+			return value;
+		}
+		if (typeof value === "number") {
+			return new Date(value);
+		}
+		if (typeof value === "string") {
+			return new Date(value);
+		}


JsonParseNode.getDateValueFromRaw returns the original Date instance when the raw value is already a Date. Previously (via new Date(this._jsonNode as string)) this always created a new Date object, so returning the same instance can leak internal references and allow callers to mutate the underlying raw value. Consider returning a cloned Date (e.g., based on getTime()) to preserve the prior copy semantics while still avoiding extra JsonParseNode allocations.

Copilot · 2026-04-08T14:43:50Z

packages/serialization/form/src/formParseNode.ts

+		// Each element from _rawString.split(",") is always a string, so we only need to
+		// decode the string values here. The result is effectively a string[].
+		const values = this._rawString.split(",").map((x) => this.getStringValueFromRaw(x));
+		return values as unknown as T[];


FormParseNode.getCollectionOfPrimitiveValues currently always returns a decoded string[] (cast to T[]). This means callers requesting number[], boolean[], Date[], etc. will still receive strings at runtime, which contradicts the ParseNode contract and how other parts of the library (e.g., response handling) may call this API for non-string primitive collections. If form content is intended to only support string primitive collections, consider throwing (or otherwise clearly failing) when non-string primitive collections are requested, or update the implementation to provide correct typed values in a non-ambiguous way.

Suggested change

// Each element from _rawString.split(",") is always a string, so we only need to

// decode the string values here. The result is effectively a string[].

const values = this._rawString.split(",").map((x) => this.getStringValueFromRaw(x));

return values as unknown as T[];

throw new Error("deserialization of primitive collections is not supported with URI encoding");

Copilot · 2026-04-08T14:43:50Z

packages/serialization/form/test/common/formParseNode.ts

+	it("getCollectionOfPrimitiveValues returns decoded string values", () => {
+		const result = new FormParseNode("one,two,three").getCollectionOfPrimitiveValues<string>();
+		assert.deepEqual(result, ["one", "two", "three"]);
+	});
+	it("getCollectionOfPrimitiveValues URL-decodes number-like string values", () => {
+		const result = new FormParseNode("1,2,3").getCollectionOfPrimitiveValues<string>();
+		assert.deepEqual(result, ["1", "2", "3"]);
+	});
+	it("getCollectionOfPrimitiveValues URL-decodes boolean-like string values", () => {
+		const result = new FormParseNode("true,false,true").getCollectionOfPrimitiveValues<string>();
+		assert.deepEqual(result, ["true", "false", "true"]);
+	});
+	it("getCollectionOfPrimitiveValues URL-decodes date-like string values", () => {
+		const result = new FormParseNode("2023-01-01,2023-06-15").getCollectionOfPrimitiveValues<string>();
+		assert.deepEqual(result, ["2023-01-01", "2023-06-15"]);
+	});


The PR description/checklist mentions adding unit tests for FormParseNode.getCollectionOfPrimitiveValues "with types other than string", but all new tests call getCollectionOfPrimitiveValues<string>() and assert string arrays. Either add tests that exercise non-string collection scenarios (if supported) or update the PR description/test wording to match the intended behavior (decoded strings only).

Initial plan

4a1f09b

Copilot AI assigned Copilot and baywet Mar 12, 2026

github-project-automation bot added this to Kiota Mar 12, 2026

Copilot started work on behalf of baywet March 12, 2026 13:48 View session

perf: reduce parse node allocations when deserializing primitive types

3ea42de

Co-authored-by: baywet <7905502+baywet@users.noreply.github.com>

Copilot AI changed the title ~~[WIP] Fix parse node allocations during primitive type deserialization~~ perf: reduce parse node allocations when deserializing primitive types Mar 12, 2026

Copilot finished work on behalf of baywet March 12, 2026 13:58

Copilot started work on behalf of baywet March 12, 2026 13:58 View session

Copilot finished work on behalf of baywet March 12, 2026 14:00

baywet requested changes Mar 12, 2026

View reviewed changes

github-project-automation bot moved this to In Progress 🚧 in Kiota Mar 12, 2026

Copilot started work on behalf of baywet March 12, 2026 18:14 View session

Copilot AI requested a review from baywet March 12, 2026 18:25

Copilot finished work on behalf of baywet March 12, 2026 18:25

baywet approved these changes Mar 17, 2026

View reviewed changes

baywet marked this pull request as ready for review March 17, 2026 13:47

baywet requested a review from a team as a code owner March 17, 2026 13:47

Copilot AI temporarily deployed to build_test March 17, 2026 13:47 Inactive

baywet requested a review from Copilot March 17, 2026 13:48

baywet enabled auto-merge March 17, 2026 13:48

Copilot started reviewing on behalf of baywet March 17, 2026 13:48 View session

Copilot AI reviewed Mar 17, 2026

View reviewed changes

chore: aligns types and raw values methods

1b2d488

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

baywet had a problem deploying to build_test March 17, 2026 13:53 — with GitHub Actions Failure

Copilot AI requested a review from baywet March 17, 2026 13:59

Copilot finished work on behalf of baywet March 17, 2026 13:59

Copilot AI reviewed Mar 17, 2026

View reviewed changes

packages/serialization/json/src/jsonParseNode.ts Outdated Show resolved Hide resolved

packages/serialization/json/src/jsonParseNode.ts Show resolved Hide resolved

packages/serialization/form/src/formParseNode.ts Outdated Show resolved Hide resolved

Copilot AI temporarily deployed to build_test March 17, 2026 14:06 Inactive

baywet requested a review from Copilot March 17, 2026 14:06

Copilot started reviewing on behalf of baywet March 17, 2026 14:07 View session

chore: avoid double parsing of dates

22d8b00

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

baywet temporarily deployed to build_test March 17, 2026 14:07 — with GitHub Actions Inactive

chore: avoid double parsing

b1fae83

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

baywet temporarily deployed to build_test March 17, 2026 14:10 — with GitHub Actions Inactive

chore: non reachable code removal

8c703fb

Co-authored-by: Copilot Autofix powered by AI <175728472+Copilot@users.noreply.github.com>

baywet had a problem deploying to build_test March 17, 2026 14:13 — with GitHub Actions Error

baywet had a problem deploying to build_test March 17, 2026 14:13 — with GitHub Actions Failure

Copilot AI reviewed Mar 17, 2026

View reviewed changes

packages/serialization/json/src/jsonParseNode.ts

return x as unknown as T;

} else if (typeOfX === "string") {

return currentParseNode.getStringValue() as unknown as T;

return x as unknown as T;

baywet requested changes Mar 17, 2026

View reviewed changes

baywet marked this pull request as draft March 17, 2026 14:15

auto-merge was automatically disabled March 17, 2026 14:15
Pull request was converted to draft

Copilot started work on behalf of baywet March 17, 2026 14:15 View session

refactor: inline single-use scalar helpers and add FormParseNode coll…

2e3673d

…ection tests Co-authored-by: baywet <7905502+baywet@users.noreply.github.com>

Copilot AI requested a review from baywet March 17, 2026 14:24

Copilot finished work on behalf of baywet March 17, 2026 14:24

Copilot AI temporarily deployed to build_test April 8, 2026 14:37 Inactive

baywet requested a review from Copilot April 8, 2026 14:37

Copilot started reviewing on behalf of baywet April 8, 2026 14:38 View session

Copilot AI reviewed Apr 8, 2026

View reviewed changes

Conversation

Copilot AI commented Mar 12, 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!

baywet commented Mar 12, 2026

Uh oh!

Copilot AI commented Mar 12, 2026

Uh oh!

baywet left a comment

Choose a reason for hiding this comment

Uh oh!

Copilot AI commented Mar 12, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI commented Mar 17, 2026

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Uh oh!

Uh oh!

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

baywet Mar 17, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 17, 2026

Choose a reason for hiding this comment

Uh oh!

baywet Mar 17, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 17, 2026

Choose a reason for hiding this comment

Uh oh!

baywet Mar 17, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Mar 17, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI left a comment

Choose a reason for hiding this comment

Pull request overview

Reviewed changes

Uh oh!

Copilot AI Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

Copilot AI Apr 8, 2026

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Copilot AI commented Mar 12, 2026 •

edited

Loading