metamask-extension chore: scan delegation delegate address in trust middleware

Description

This PR extends the trust signals middleware to scan delegate addresses when processing delegation signatures (EIP-7710 Delegations).

Reason for the change: When a user signs a delegation, the delegate address is a critical security parameter—it determines who will have delegated authority over the user's account. Currently, the trust signals middleware scans verifying contracts and spender addresses (for permits), but does not scan the delegate address in delegation signatures. This leaves a gap in our security scanning coverage.

Improvement/solution:

Extended handleEthSignTypedData in the trust signals middleware to detect delegation signatures (via PRIMARY_TYPE_DELEGATION) and scan the delegate address using the existing scanAddressAndAddToCache mechanism
Exported PRIMARY_TYPE_DELEGATION constant from delegation.ts to enable reuse across modules
Added comprehensive test coverage for the new functionality, including:
- Verifying both the verifying contract and delegate addresses are scanned
- Graceful error handling when delegate scanning fails
- Edge case handling when delegate address is not present

The implementation follows the existing patterns established for permit signature scanning.

Changelog

CHANGELOG entry: null

Manual testing steps

Create a new permission and sign it.
In the signing step delegate scan should be triggered.

Screenshots/Recordings

Before

After

Pre-merge author checklist

[x] I've followed MetaMask Contributor Docs and MetaMask Extension Coding Standards.
[x] I've completed the PR template to the best of my ability
[x] I’ve included tests if applicable
[x] I’ve documented my code using JSDoc format if applicable
[x] I’ve applied the right labels on the PR (see labeling guidelines). Not required for external contributors.

Pre-merge reviewer checklist

[ ] I've manually tested the PR (e.g. pull and build branch, run the app, test code being changed).
[ ] I confirm that this PR addresses all acceptance criteria described in the ticket it closes and includes the necessary testing evidence such as recordings and or screenshots.

[!NOTE] Scan delegate addresses for delegation typed-data signatures and export PRIMARY_TYPE_DELEGATION, with comprehensive tests and error handling.

Trust Signals Middleware:

Scan delegate address for EIP-712 delegation signatures (primaryType: "Delegation") alongside the verifyingContract.

Leverages PRIMARY_TYPE_DELEGATION for detection and adds graceful error handling on delegate scan failures.

Transactions/Delegation:

Export PRIMARY_TYPE_DELEGATION from app/scripts/lib/transaction/delegation.ts for cross-module use.

Tests:

Add tests to verify scanning of both verifyingContract and delegate, error handling on delegate scan failures, and no-scan when delegate is absent.

Introduce DELEGATE test address constant.

^{Written by Cursor Bugbot for commit 80403528581456031b2d522ea83ce9245cd6a359. This will update automatically on new commits. Configure here.}

Dec 10 '25 12:12 MoMannn

CLA Signature Action: All authors have signed the CLA. You may need to manually re-run the blocking PR check if it doesn't pass in a few minutes.

Dec 10 '25 12:12 github-actions[bot]

Builds ready [8040352]

builds: chrome, firefox
builds (beta): chrome, firefox
builds (flask): chrome, firefox
builds (test): chrome, firefox
builds (test-flask): chrome, firefox
bundle size: Bundle Size Stats
user-actions-benchmark: User Actions Stats
storybook: Storybook
typescript migration: Dashboard
all artifacts
bundle viz:
- background: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
- common: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
- ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18
- content-script: 0
- offscreen: 0

UI Startup Metrics (1261 ± 102 ms)

Platform	BuildType	Page	Metric	Mean (ms)	Min (ms)	Max (ms)	Std Dev (ms)	P 75 (ms)	P 95 (ms)
Chrome	Browserify	Standard Home	uiStartup	1261	1059	1536	102	1321	1428
			load	1034	864	1290	89	1082	1218
			domContentLoaded	1026	858	1283	86	1072	1200
			domInteractive	25	15	117	20	20	82
			firstPaint	509	78	1242	404	1001	1167
			backgroundConnect	214	198	280	14	218	242
			firstReactRender	49	31	235	24	54	81
			getState	43	18	140	27	47	125
			initialActions	1	0	4	1	1	2
			loadScripts	820	660	1082	85	864	996
			setupStore	13	6	29	5	16	23
			numNetworkReqs	14	6	89	20	6	75
	Browserify	Power User Home	uiStartup	-	-	-	-	-	-
			load	-	-	-	-	-	-
			domContentLoaded	-	-	-	-	-	-
			domInteractive	-	-	-	-	-	-
			firstPaint	-	-	-	-	-	-
			backgroundConnect	-	-	-	-	-	-
			firstReactRender	-	-	-	-	-	-
			getState	-	-	-	-	-	-
			initialActions	-	-	-	-	-	-
			loadScripts	-	-	-	-	-	-
			setupStore	-	-	-	-	-	-
			numNetworkReqs	-	-	-	-	-	-
	Webpack	Standard Home	uiStartup	819	680	1230	94	871	954
			load	657	572	1020	87	705	796
			domContentLoaded	651	569	1016	86	700	789
			domInteractive	26	15	93	18	23	84
			firstPaint	243	85	1009	175	229	647
			backgroundConnect	11	6	80	9	12	28
			firstReactRender	54	33	214	29	67	118
			getState	28	14	63	11	37	47
			initialActions	1	0	4	1	1	2
			loadScripts	648	566	1014	85	696	780
			setupStore	12	4	57	7	13	27
			numNetworkReqs	13	6	79	19	6	68
	Webpack	Power User Home	uiStartup	1425	1086	2053	199	1584	1744
			load	741	604	985	98	830	904
			domContentLoaded	734	598	975	98	824	896
			domInteractive	32	17	131	26	27	108
			firstPaint	272	84	867	181	287	680
			backgroundConnect	84	7	716	169	47	583
			firstReactRender	51	40	72	6	54	64
			getState	194	137	699	63	205	276
			initialActions	1	0	3	1	1	2
			loadScripts	730	596	973	97	817	894
			setupStore	17	7	46	9	16	36
			numNetworkReqs	72	56	214	25	67	135
Firefox	Browserify	Standard Home	uiStartup	1348	1072	2299	192	1418	1696
			load	1086	907	2030	140	1143	1277
			domContentLoaded	1086	907	2030	140	1143	1277
			domInteractive	75	31	958	97	86	139
			firstPaint	-	-	-	-	-	-
			backgroundConnect	56	20	263	46	66	169
			firstReactRender	39	29	67	8	39	60
			getState	13	7	90	11	12	36
			initialActions	1	0	2	1	2	2
			loadScripts	1055	892	1928	128	1114	1205
			setupStore	15	5	151	21	13	40
			numNetworkReqs	15	6	82	21	8	76
	Browserify	Power User Home	uiStartup	2638	1678	3402	516	3048	3311
			load	1642	936	2504	502	2124	2391
			domContentLoaded	1641	936	2503	502	2122	2390
			domInteractive	172	31	990	283	95	979
			firstPaint	-	-	-	-	-	-
			backgroundConnect	176	20	1187	205	185	467
			firstReactRender	66	36	973	93	60	96
			getState	122	65	346	45	138	219
			initialActions	2	0	3	1	2	3
			loadScripts	1552	921	2488	474	2009	2236
			setupStore	43	4	467	73	43	223
			numNetworkReqs	74	54	131	19	79	117
	Webpack	Standard Home	uiStartup	1603	1300	2842	195	1711	1899
			load	1320	1112	2590	159	1382	1465
			domContentLoaded	1320	1107	2590	159	1382	1464
			domInteractive	78	28	231	40	106	144
			firstPaint	-	-	-	-	-	-
			backgroundConnect	57	22	204	36	66	149
			firstReactRender	43	33	98	10	47	56
			getState	17	8	114	18	14	60
			initialActions	1	0	3	1	2	2
			loadScripts	1290	1098	2569	158	1354	1433
			setupStore	18	6	145	24	15	78
			numNetworkReqs	15	6	79	20	8	72
	Webpack	Power User Home	uiStartup	2830	1732	4455	571	3265	3592
			load	1926	1096	2816	464	2318	2624
			domContentLoaded	1926	1096	2816	464	2318	2623
			domInteractive	179	32	988	276	127	918
			firstPaint	-	-	-	-	-	-
			backgroundConnect	183	27	1162	233	196	887
			firstReactRender	62	42	133	15	66	97
			getState	139	67	895	92	161	231
			initialActions	3	1	40	5	3	7
			loadScripts	1830	1080	2714	444	2216	2504
			setupStore	62	7	470	100	61	351
			numNetworkReqs	71	47	146	25	65	125

📊 Page Load Benchmark Results

Current Commit: 8040352 | Date: 12/10/2025

📄 Localhost MetaMask Test Dapp

Samples: 100

Summary

pageLoadTime-> current mean value: 1.03s (±39ms) 🟡 | historical mean value: 1.04s ⬇️ (historical data)
domContentLoaded-> current mean value: 719ms (±37ms) 🟢 | historical mean value: 721ms ⬇️ (historical data)
firstContentfulPaint-> current mean value: 77ms (±14ms) 🟢 | historical mean value: 79ms ⬇️ (historical data)

📈 Detailed Results

Metric	Mean	Std Dev	Min	Max	P95	P99
pageLoadTime	1.03s	39ms	1.00s	1.32s	1.08s	1.32s
domContentLoaded	719ms	37ms	692ms	990ms	739ms	990ms
firstPaint	77ms	14ms	60ms	200ms	84ms	200ms
firstContentfulPaint	77ms	14ms	60ms	200ms	84ms	200ms
largestContentfulPaint	0ms	0ms	0ms	0ms	0ms	0ms

Bundle size diffs [🚨 Warning! Bundle size has increased!]

background: 3.08 KiB (0.06%)
ui: -2.55 KiB (-0.03%)
common: -739 Bytes (-0.01%)

Dec 10 '25 12:12 metamaskbot

Builds ready [8040352]

builds: chrome, firefox
builds (beta): chrome, firefox
builds (flask): chrome, firefox
builds (test): chrome, firefox
builds (test-flask): chrome, firefox
bundle size: Bundle Size Stats
user-actions-benchmark: User Actions Stats
storybook: Storybook
typescript migration: Dashboard
all artifacts
bundle viz:
- background: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9
- common: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15
- ui: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18
- content-script: 0
- offscreen: 0

UI Startup Metrics (1261 ± 102 ms)

Platform	BuildType	Page	Metric	Mean (ms)	Min (ms)	Max (ms)	Std Dev (ms)	P 75 (ms)	P 95 (ms)
Chrome	Browserify	Standard Home	uiStartup	1261	1059	1536	102	1321	1428
			load	1034	864	1290	89	1082	1218
			domContentLoaded	1026	858	1283	86	1072	1200
			domInteractive	25	15	117	20	20	82
			firstPaint	509	78	1242	404	1001	1167
			backgroundConnect	214	198	280	14	218	242
			firstReactRender	49	31	235	24	54	81
			getState	43	18	140	27	47	125
			initialActions	1	0	4	1	1	2
			loadScripts	820	660	1082	85	864	996
			setupStore	13	6	29	5	16	23
			numNetworkReqs	14	6	89	20	6	75
	Browserify	Power User Home	uiStartup	1905	1637	2235	140	1981	2156
			load	1060	885	1335	119	1153	1264
			domContentLoaded	1051	872	1317	119	1143	1257
			domInteractive	29	17	125	22	25	89
			firstPaint	533	100	1348	417	998	1231
			backgroundConnect	256	198	677	105	238	567
			firstReactRender	47	38	107	8	49	57
			getState	186	137	353	31	199	244
			initialActions	1	0	8	1	1	2
			loadScripts	840	674	1119	118	936	1058
			setupStore	15	7	64	8	15	35
			numNetworkReqs	72	57	137	19	70	133
	Webpack	Standard Home	uiStartup	819	680	1230	94	871	954
			load	657	572	1020	87	705	796
			domContentLoaded	651	569	1016	86	700	789
			domInteractive	26	15	93	18	23	84
			firstPaint	243	85	1009	175	229	647
			backgroundConnect	11	6	80	9	12	28
			firstReactRender	54	33	214	29	67	118
			getState	28	14	63	11	37	47
			initialActions	1	0	4	1	1	2
			loadScripts	648	566	1014	85	696	780
			setupStore	12	4	57	7	13	27
			numNetworkReqs	13	6	79	19	6	68
	Webpack	Power User Home	uiStartup	1425	1086	2053	199	1584	1744
			load	741	604	985	98	830	904
			domContentLoaded	734	598	975	98	824	896
			domInteractive	32	17	131	26	27	108
			firstPaint	272	84	867	181	287	680
			backgroundConnect	84	7	716	169	47	583
			firstReactRender	51	40	72	6	54	64
			getState	194	137	699	63	205	276
			initialActions	1	0	3	1	1	2
			loadScripts	730	596	973	97	817	894
			setupStore	17	7	46	9	16	36
			numNetworkReqs	72	56	214	25	67	135
Firefox	Browserify	Standard Home	uiStartup	1348	1072	2299	192	1418	1696
			load	1086	907	2030	140	1143	1277
			domContentLoaded	1086	907	2030	140	1143	1277
			domInteractive	75	31	958	97	86	139
			firstPaint	-	-	-	-	-	-
			backgroundConnect	56	20	263	46	66	169
			firstReactRender	39	29	67	8	39	60
			getState	13	7	90	11	12	36
			initialActions	1	0	2	1	2	2
			loadScripts	1055	892	1928	128	1114	1205
			setupStore	15	5	151	21	13	40
			numNetworkReqs	15	6	82	21	8	76
	Browserify	Power User Home	uiStartup	2638	1678	3402	516	3048	3311
			load	1642	936	2504	502	2124	2391
			domContentLoaded	1641	936	2503	502	2122	2390
			domInteractive	172	31	990	283	95	979
			firstPaint	-	-	-	-	-	-
			backgroundConnect	176	20	1187	205	185	467
			firstReactRender	66	36	973	93	60	96
			getState	122	65	346	45	138	219
			initialActions	2	0	3	1	2	3
			loadScripts	1552	921	2488	474	2009	2236
			setupStore	43	4	467	73	43	223
			numNetworkReqs	74	54	131	19	79	117
	Webpack	Standard Home	uiStartup	1603	1300	2842	195	1711	1899
			load	1320	1112	2590	159	1382	1465
			domContentLoaded	1320	1107	2590	159	1382	1464
			domInteractive	78	28	231	40	106	144
			firstPaint	-	-	-	-	-	-
			backgroundConnect	57	22	204	36	66	149
			firstReactRender	43	33	98	10	47	56
			getState	17	8	114	18	14	60
			initialActions	1	0	3	1	2	2
			loadScripts	1290	1098	2569	158	1354	1433
			setupStore	18	6	145	24	15	78
			numNetworkReqs	15	6	79	20	8	72
	Webpack	Power User Home	uiStartup	2830	1732	4455	571	3265	3592
			load	1926	1096	2816	464	2318	2624
			domContentLoaded	1926	1096	2816	464	2318	2623
			domInteractive	179	32	988	276	127	918
			firstPaint	-	-	-	-	-	-
			backgroundConnect	183	27	1162	233	196	887
			firstReactRender	62	42	133	15	66	97
			getState	139	67	895	92	161	231
			initialActions	3	1	40	5	3	7
			loadScripts	1830	1080	2714	444	2216	2504
			setupStore	62	7	470	100	61	351
			numNetworkReqs	71	47	146	25	65	125

📊 Page Load Benchmark Results

Current Commit: 8040352 | Date: 12/10/2025

📄 Localhost MetaMask Test Dapp

Samples: 100

Summary

pageLoadTime-> current mean value: 1.03s (±39ms) 🟡 | historical mean value: 1.03s ⬇️ (historical data)
domContentLoaded-> current mean value: 719ms (±37ms) 🟢 | historical mean value: 722ms ⬇️ (historical data)
firstContentfulPaint-> current mean value: 77ms (±14ms) 🟢 | historical mean value: 80ms ⬇️ (historical data)

📈 Detailed Results

Metric	Mean	Std Dev	Min	Max	P95	P99
pageLoadTime	1.03s	39ms	1.00s	1.32s	1.08s	1.32s
domContentLoaded	719ms	37ms	692ms	990ms	739ms	990ms
firstPaint	77ms	14ms	60ms	200ms	84ms	200ms
firstContentfulPaint	77ms	14ms	60ms	200ms	84ms	200ms
largestContentfulPaint	0ms	0ms	0ms	0ms	0ms	0ms

Bundle size diffs [🚨 Warning! Bundle size has increased!]

background: 3.08 KiB (0.06%)
ui: -2.55 KiB (-0.03%)
common: -739 Bytes (-0.01%)

Dec 11 '25 13:12 metamaskbot