Fix PushDrop.decode to support lockPosition='after' parameter

[Stephen-Thomson]

Description of Changes

• PushDrop.decode() now accepts an optional lockPosition parameter ('before' | 'after', defaults to 'before')
• When lockPosition='after', the method correctly finds the public key at the end of the script (before OP_CHECKSIG) instead of assuming it's at the beginning
• This fixes the "Unknown point format" error that occurred when trying to decode scripts created with lockPosition='after'

Linked Issues / Tickets

Closes Issue #259

Testing Procedure

• Added test case: "decodes the locking script correctly with lockPosition after"

• I have added new unit tests

• All tests pass locally

• I have tested manually in my local environment

Checklist

• I have performed a self-review of my own code
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• I have updated CHANGELOG.md with my changes
• I have run npm run doc and npm run lint one final time before requesting a review
• I have fixed all linter errors to ensure these changes are compliant with ts-standard
• I have run npm version patch so that my changes will trigger a new version to be released when they are merged

[codecov]

Codecov Report

❌ Patch coverage is 88.88889% with 2 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
src/script/templates/PushDrop.ts	92.85%	1 Missing ⚠️
src/transaction/broadcasters/ARC.ts	75.00%	1 Missing ⚠️

📢 Thoughts on this report? Let us know!

[github-actions]

🏁 Benchmark Comparison (Node 22)

Comparing this PR (303c958) against master (fe07829).

✅ No regressions over the 5% threshold detected.

Benchmark	Metric	PR Branch	Master	Δ	Change
BigNumber Arithmetic	mul large numbers	8.89 ms	8.90 ms	-0.01 ms	-0.11%
BigNumber Arithmetic	add large numbers	1.49 ms	1.49 ms	+0.00 ms	0.00%
BigNumber Serialization	toSm big	3.08 ms	3.07 ms	+0.01 ms	+0.33%
BigNumber Serialization	toSm little	3.15 ms	3.15 ms	+0.00 ms	0.00%
BigNumber Serialization	fromSm big	3.17 ms	3.15 ms	+0.02 ms	+0.63%
BigNumber Serialization	fromSm little	3.26 ms	3.30 ms	-0.04 ms	-1.21%
BigNumber Serialization	fromScriptNum	3.19 ms	3.22 ms	-0.03 ms	-0.93%
Script Serialization	Big script round trip	4.01 ms	4.02 ms	-0.01 ms	-0.25%
Transaction Verification	deep chain verify	582.21 ms	579.39 ms	+2.82 ms	+0.49%
Transaction Verification	wide transaction verify	594.96 ms	599.64 ms	-4.68 ms	-0.78%
Transaction Verification	large tx verify	292.72 ms	295.69 ms	-2.97 ms	-1.00%
Transaction Verification	nested inputs verify	169.38 ms	164.05 ms	+5.33 ms	+3.25%
Symmetric Key	encrypt large 2MB	1769.18 ms	1752.99 ms	+16.19 ms	+0.92%
Symmetric Key	decrypt large 2MB	1723.34 ms	1714.96 ms	+8.38 ms	+0.49%
Symmetric Key	encrypt 50 small	7.72 ms	7.67 ms	+0.05 ms	+0.65%
Symmetric Key	decrypt 50 small	7.31 ms	7.16 ms	+0.15 ms	+2.09%
Symmetric Key	encrypt 200 medium	185.99 ms	185.97 ms	+0.02 ms	+0.01%
Symmetric Key	decrypt 200 medium	183.22 ms	177.54 ms	+5.68 ms	+3.20%
Reader & Writer	mixed ops	0.23 ms	0.23 ms	+0.00 ms	0.00%
Reader & Writer	large payloads	31.18 ms	31.15 ms	+0.03 ms	+0.10%
Reader & Writer	3000 small payloads	1.89 ms	1.89 ms	+0.00 ms	0.00%
Reader & Writer	400 medium payloads	17.12 ms	16.93 ms	+0.19 ms	+1.12%
Atomic BEEF	Transaction.toAtomicBEEF	1.59 ms	1.61 ms	-0.02 ms	-1.24%
Atomic BEEF	Transaction.fromAtomicBEEF	3.70 ms	3.73 ms	-0.03 ms	-0.80%

[github-actions]

🏁 Benchmark Comparison (Node 22)

Comparing this PR (2a68c5f) against master (fe07829).

⚠️ 1 regression detected (>5% slower).

Regressions

• ⚠️ Atomic BEEF – Transaction.fromAtomicBEEF is 10.38% slower (4.04 ms vs 3.66 ms).

Benchmark	Metric	PR Branch	Master	Δ	Change
BigNumber Arithmetic	mul large numbers	8.93 ms	8.87 ms	+0.06 ms	+0.68%
BigNumber Arithmetic	add large numbers	1.47 ms	1.48 ms	-0.01 ms	-0.68%
BigNumber Serialization	toSm big	3.01 ms	3.01 ms	+0.00 ms	0.00%
BigNumber Serialization	toSm little	3.11 ms	3.08 ms	+0.03 ms	+0.97%
BigNumber Serialization	fromSm big	3.08 ms	3.10 ms	-0.02 ms	-0.65%
BigNumber Serialization	fromSm little	3.17 ms	3.14 ms	+0.03 ms	+0.96%
BigNumber Serialization	fromScriptNum	3.22 ms	3.20 ms	+0.02 ms	+0.63%
Script Serialization	Big script round trip	3.92 ms	3.87 ms	+0.05 ms	+1.29%
Transaction Verification	deep chain verify	581.19 ms	577.56 ms	+3.63 ms	+0.63%
Transaction Verification	wide transaction verify	591.26 ms	588.10 ms	+3.16 ms	+0.54%
Transaction Verification	large tx verify	292.42 ms	290.48 ms	+1.94 ms	+0.67%
Transaction Verification	nested inputs verify	162.26 ms	161.75 ms	+0.51 ms	+0.32%
Symmetric Key	encrypt large 2MB	1753.57 ms	1745.77 ms	+7.80 ms	+0.45%
Symmetric Key	decrypt large 2MB	1707.71 ms	1693.72 ms	+13.99 ms	+0.83%
Symmetric Key	encrypt 50 small	7.55 ms	7.53 ms	+0.02 ms	+0.27%
Symmetric Key	decrypt 50 small	7.18 ms	7.14 ms	+0.04 ms	+0.56%
Symmetric Key	encrypt 200 medium	184.49 ms	182.32 ms	+2.17 ms	+1.19%
Symmetric Key	decrypt 200 medium	179.82 ms	177.46 ms	+2.36 ms	+1.33%
Reader & Writer	mixed ops	0.22 ms	0.23 ms	-0.01 ms	-4.35%
Reader & Writer	large payloads	28.94 ms	29.21 ms	-0.27 ms	-0.92%
Reader & Writer	3000 small payloads	1.76 ms	1.75 ms	+0.01 ms	+0.57%
Reader & Writer	400 medium payloads	15.45 ms	15.32 ms	+0.13 ms	+0.85%
Atomic BEEF	Transaction.toAtomicBEEF	1.53 ms	1.52 ms	+0.01 ms	+0.66%
Atomic BEEF	Transaction.fromAtomicBEEF	4.04 ms	3.66 ms	+0.38 ms	+10.38%

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[github-actions]

🏁 Benchmark Comparison (Node 22)

Comparing this PR (55b3a97) against master (fe07829).

✅ No regressions over the 5% threshold detected.

Benchmark	Metric	PR Branch	Master	Δ	Change
BigNumber Arithmetic	mul large numbers	8.80 ms	8.80 ms	+0.00 ms	0.00%
BigNumber Arithmetic	add large numbers	1.44 ms	1.45 ms	-0.01 ms	-0.69%
BigNumber Serialization	toSm big	2.81 ms	2.81 ms	+0.00 ms	0.00%
BigNumber Serialization	toSm little	2.91 ms	2.86 ms	+0.05 ms	+1.75%
BigNumber Serialization	fromSm big	2.91 ms	2.93 ms	-0.02 ms	-0.68%
BigNumber Serialization	fromSm little	3.01 ms	3.02 ms	-0.01 ms	-0.33%
BigNumber Serialization	fromScriptNum	3.00 ms	3.01 ms	-0.01 ms	-0.33%
Script Serialization	Big script round trip	3.74 ms	3.77 ms	-0.03 ms	-0.80%
Transaction Verification	deep chain verify	572.22 ms	569.67 ms	+2.55 ms	+0.45%
Transaction Verification	wide transaction verify	581.97 ms	583.63 ms	-1.66 ms	-0.28%
Transaction Verification	large tx verify	289.45 ms	290.30 ms	-0.85 ms	-0.29%
Transaction Verification	nested inputs verify	161.11 ms	161.08 ms	+0.03 ms	+0.02%
Symmetric Key	encrypt large 2MB	1741.82 ms	1752.79 ms	-10.97 ms	-0.63%
Symmetric Key	decrypt large 2MB	1699.05 ms	1702.79 ms	-3.74 ms	-0.22%
Symmetric Key	encrypt 50 small	7.54 ms	7.46 ms	+0.08 ms	+1.07%
Symmetric Key	decrypt 50 small	7.14 ms	7.14 ms	+0.00 ms	0.00%
Symmetric Key	encrypt 200 medium	182.76 ms	180.84 ms	+1.92 ms	+1.06%
Symmetric Key	decrypt 200 medium	176.54 ms	176.34 ms	+0.20 ms	+0.11%
Reader & Writer	mixed ops	0.21 ms	0.21 ms	+0.00 ms	0.00%
Reader & Writer	large payloads	27.14 ms	27.45 ms	-0.31 ms	-1.13%
Reader & Writer	3000 small payloads	1.66 ms	1.69 ms	-0.03 ms	-1.78%
Reader & Writer	400 medium payloads	13.87 ms	13.89 ms	-0.02 ms	-0.14%
Atomic BEEF	Transaction.toAtomicBEEF	1.47 ms	1.48 ms	-0.01 ms	-0.68%
Atomic BEEF	Transaction.fromAtomicBEEF	3.58 ms	3.61 ms	-0.03 ms	-0.83%