fix: debug_traceTransaction default param by macfarla · Pull Request #9788 · hyperledger/besu

macfarla · 2026-02-11T23:59:23Z

PR description

When reviewing docs PR 1909, claude picked up an inconsistency with default parameters when no params are supplied vs empty {} params - as described in #9787

Docs still needs correcting here to say disableMemory is true by default (all other booleans default to false) https://besu.hyperledger.org/public-networks/reference/api#debug_tracetransaction

Fixed Issue(s)

fixes #9787

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Checked out our contribution guidelines?
Considered documentation and added the doc-change-required label to this PR if updates are required.
Considered the changelog and included an update if required.
For database changes (e.g. KeyValueSegmentIdentifier) considered compatibility and performed forwards and backwards compatibility tests

Locally, you can run these tests to catch failures early:

spotless: ./gradlew spotlessApply
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acceptance tests: ./gradlew acceptanceTest
integration tests: ./gradlew integrationTest
reference tests: ./gradlew ethereum:referenceTests:referenceTests
hive tests: Engine or other RPCs modified?

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

…ue, matching the documented API behavior Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

usmansaleem

LGTM

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

…x-empty-options

I have pushed more changes

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

macfarla · 2026-02-13T01:26:31Z

@lu-pinto can you review this one - the default param behavior is currently inconsistent between RPCs - this came up from looking at a docs PR hyperledger/besu-docs#1909 - in one spot we say the trace flags are all false by default but looking at the code that's not the case, and actually you currently get different behavior between passing no options and empty {} options

...va/org/hyperledger/besu/ethereum/api/jsonrpc/internal/parameters/TransactionTraceParams.java

lu-pinto

Looks good, I think the default behavior for Geth is also to not show memory if not enabled. Make sense to align cases with empty params with no params at all

…x-empty-options

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

Copilot

Pull request overview

Fixes debug_traceTransaction option-default behavior so debug_traceTransaction(hash) and debug_traceTransaction(hash,{}) behave consistently, and adjusts memory tracing defaults for non-opcode tracers.

Changes:

Update TransactionTraceParams#traceOptions() to only override tracer defaults when a user explicitly supplies disable* fields, and to enable memory by default for non-opcode tracers unless explicitly disabled.
Add unit tests covering {} vs defaults and callTracer memory-default behavior.
Update JSON-RPC trace fixtures to reflect the new effective defaults (notably memory capture changes).

Reviewed changes

Copilot reviewed 7 out of 7 changed files in this pull request and generated 4 comments.

Show a summary per file

File	Description
ethereum/api/src/main/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/parameters/TransactionTraceParams.java	Adjusts how trace options are derived so explicit vs missing params behave consistently; enables memory for non-opcode tracers by default.
ethereum/api/src/test/java/org/hyperledger/besu/ethereum/api/jsonrpc/internal/parameters/TransactionTraceParamsTest.java	Adds coverage for `{}` matching defaults, opcode tracer defaults, and callTracer memory behavior.
ethereum/api/src/test/resources/org/hyperledger/besu/ethereum/api/jsonrpc/debug/trace-transaction/debug_traceTransaction_disableStorage.json	Updates expected trace output with memory fields omitted per new defaults.
ethereum/api/src/test/resources/org/hyperledger/besu/ethereum/api/jsonrpc/debug/trace-transaction/debug_traceTransaction_disableStack.json	Updates expected trace output with memory fields omitted per new defaults.
ethereum/api/src/test/resources/org/hyperledger/besu/ethereum/api/jsonrpc/debug/trace-call/debug_traceCall_stateOverride.json	Updates expected trace output with memory fields omitted per new defaults.
ethereum/api/src/test/resources/org/hyperledger/besu/ethereum/api/jsonrpc/debug/trace-call/debug_traceCall_disableStorage.json	Updates expected trace output with memory fields omitted per new defaults.
ethereum/api/src/test/resources/org/hyperledger/besu/ethereum/api/jsonrpc/debug/trace-call/debug_traceCall_disableStack.json	Updates expected trace output with memory fields omitted per new defaults.

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Copilot · 2026-02-24T02:39:00Z

...rg/hyperledger/besu/ethereum/api/jsonrpc/internal/parameters/TransactionTraceParamsTest.java

+    // Passing {} should be equivalent to passing no options at all.
+    // All disable* fields default to false, so all tracing is enabled by default.
+    final OpCodeTracerConfig defaultConfig = TraceOptions.DEFAULT.opCodeTracerConfig();
+
+    // Parse an empty JSON options object — simulates debug_traceTransaction(hash, {})
+    final TransactionTraceParams emptyParams = MAPPER.readValue("{}", TransactionTraceParams.class);
+    final OpCodeTracerConfig emptyParamsConfig = emptyParams.traceOptions().opCodeTracerConfig();
+


The comment about defaults is inaccurate/misleading: TraceOptions.DEFAULT has traceMemory() disabled by default (and per PR description, disableMemory is effectively true by default when omitted). Consider updating the comment to reflect that {} should match TraceOptions.DEFAULT, where memory tracing may still be off by default.

Suggested change

// Passing {} should be equivalent to passing no options at all.

// All disable* fields default to false, so all tracing is enabled by default.

final OpCodeTracerConfig defaultConfig = TraceOptions.DEFAULT.opCodeTracerConfig();

// Parse an empty JSON options object — simulates debug_traceTransaction(hash, {})

final TransactionTraceParams emptyParams = MAPPER.readValue("{}", TransactionTraceParams.class);

final OpCodeTracerConfig emptyParamsConfig = emptyParams.traceOptions().opCodeTracerConfig();

// Passing {} should be equivalent to passing no options at all and therefore

// should produce the same behavior as TraceOptions.DEFAULT (including that

// memory tracing may be disabled by default).

final OpCodeTracerConfig defaultConfig = TraceOptions.DEFAULT.opCodeTracerConfig();

// Parse an empty JSON options object — simulates debug_traceTransaction(hash, {})

final TransactionTraceParams emptyParams = MAPPER.readValue("{}", TransactionTraceParams.class);

final OpCodeTracerConfig emptyParamsConfig = emptyParams.traceOptions().opCodeTracerConfig();

Copilot · 2026-02-24T02:39:01Z

...rg/hyperledger/besu/ethereum/api/jsonrpc/internal/parameters/TransactionTraceParamsTest.java

+
+    assertThat(defaultConfig.traceStorage()).isTrue();
+    assertThat(defaultConfig.traceMemory()).isFalse();
+    assertThat(defaultConfig.traceStack()).isTrue();


This test hard-codes the expected default booleans, which can make it brittle if OpCodeTracerConfig.DEFAULT changes. A more stable assertion would compare each field directly against OpCodeTracerConfig.DEFAULT (or assert object equality if supported), so the test continues to validate the relationship rather than specific constant values.

Suggested change

assertThat(defaultConfig.traceStorage()).isTrue();

assertThat(defaultConfig.traceMemory()).isFalse();

assertThat(defaultConfig.traceStack()).isTrue();

final OpCodeTracerConfig expectedConfig = OpCodeTracerConfig.DEFAULT;

assertThat(defaultConfig.traceStorage()).isEqualTo(expectedConfig.traceStorage());

assertThat(defaultConfig.traceMemory()).isEqualTo(expectedConfig.traceMemory());

assertThat(defaultConfig.traceStack()).isEqualTo(expectedConfig.traceStack());

Copilot · 2026-02-24T02:39:01Z

...va/org/hyperledger/besu/ethereum/api/jsonrpc/internal/parameters/TransactionTraceParams.java

+    if (disableStorageNullable() != null) {
+      builder.traceStorage(!disableStorage());
+    }
+    if (disableMemoryNullable() != null) {
+      builder.traceMemory(!disableMemory());
+    } else if (tracerType != TracerType.OPCODE_TRACER) {
+      // Non-opcode tracers (e.g. callTracer) need memory capture enabled for internal
+      // operations such as extracting CREATE init code, even when disableMemory is not set
+      builder.traceMemory(true);
+    }
+    if (disableStackNullable() != null) {
+      builder.traceStack(!disableStack());


Inside the *_Nullable() != null branches, consider using the nullable value you just checked (e.g., disableStorageNullable() / disableMemoryNullable()) rather than calling the separate boolean accessors again. This avoids any chance of diverging logic between the nullable and primitive getters and makes it clearer that you're applying only explicitly provided values.

Suggested change

if (disableStorageNullable() != null) {

builder.traceStorage(!disableStorage());

}

if (disableMemoryNullable() != null) {

builder.traceMemory(!disableMemory());

} else if (tracerType != TracerType.OPCODE_TRACER) {

// Non-opcode tracers (e.g. callTracer) need memory capture enabled for internal

// operations such as extracting CREATE init code, even when disableMemory is not set

builder.traceMemory(true);

}

if (disableStackNullable() != null) {

builder.traceStack(!disableStack());

final Boolean disableStorage = disableStorageNullable();

if (disableStorage != null) {

builder.traceStorage(!disableStorage);

}

final Boolean disableMemory = disableMemoryNullable();

if (disableMemory != null) {

builder.traceMemory(!disableMemory);

} else if (tracerType != TracerType.OPCODE_TRACER) {

// Non-opcode tracers (e.g. callTracer) need memory capture enabled for internal

// operations such as extracting CREATE init code, even when disableMemory is not set

builder.traceMemory(true);

}

final Boolean disableStack = disableStackNullable();

if (disableStack != null) {

builder.traceStack(!disableStack);

Copilot · 2026-02-24T02:39:01Z

...besu/ethereum/api/jsonrpc/debug/trace-transaction/debug_traceTransaction_disableStorage.json

        "gas" : 292515,
        "gasCost" : 6,
        "depth" : 1,
-        "stack" : [ "0x9dc2c8f5", "0x227", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b", "0x1", "0x0", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe9", "0x0" ],
-        "memory" : [ "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe9" ]
+        "stack" : [ "0x9dc2c8f5", "0x227", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffff", "0xa94f5374fce5edbc8e2a8697c15331677e6ebf0b", "0x1", "0x0", "0xffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffffe9", "0x0" ]


This fixture is named *_disableStorage.json but the updated expected output also reflects the default omission of memory (i.e., not just storage being disabled). To reduce confusion for future readers, consider renaming the fixture (or, if the test intent is strictly 'disableStorage only', adjust the underlying request in the fixture to explicitly set disableMemory: false so the name matches the behavior under test).

macfarla added 3 commits February 12, 2026 08:40

added test to demonstrate the problem

8c21d15

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

only override defaults when user explicitly provides a value

e8f74ab

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

memory off by default

b31bf13

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

macfarla marked this pull request as draft February 12, 2026 00:51

macfarla added 2 commits February 12, 2026 11:23

adjust tests; Changed TraceOptions.DEFAULT to override traceMemory=tr…

a522775

…ue, matching the documented API behavior Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

fix failing test

9ef10b7

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

macfarla marked this pull request as ready for review February 12, 2026 05:42

usmansaleem previously approved these changes Feb 12, 2026

View reviewed changes

macfarla assigned lu-pinto Feb 12, 2026

macfarla marked this pull request as draft February 12, 2026 23:28

macfarla added 2 commits February 13, 2026 09:55

memory off by default

81a0e4a

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

Merge branch 'main' of github.com:hyperledger/besu into debug-trace-t…

c0645c6

…x-empty-options

macfarla requested a review from usmansaleem February 12, 2026 23:59

add nuance for tracecall tracer params

df49ac9

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

macfarla marked this pull request as ready for review February 13, 2026 01:26

macfarla mentioned this pull request Feb 13, 2026

documents debug file traces hyperledger/besu-docs#1909

Merged

lu-pinto reviewed Feb 23, 2026

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...va/org/hyperledger/besu/ethereum/api/jsonrpc/internal/parameters/TransactionTraceParams.java Outdated Show resolved Hide resolved

lu-pinto approved these changes Feb 23, 2026

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macfarla assigned macfarla and unassigned lu-pinto Feb 23, 2026

macfarla added 2 commits February 24, 2026 12:23

Merge branch 'main' of github.com:hyperledger/besu into debug-trace-t…

1d7da12

…x-empty-options

rename

42ef372

Signed-off-by: Sally MacFarlane <macfarla.github@gmail.com>

Copilot AI review requested due to automatic review settings February 24, 2026 02:33

macfarla enabled auto-merge (squash) February 24, 2026 02:35

Copilot AI reviewed Feb 24, 2026

View reviewed changes

macfarla merged commit 182c1a7 into hyperledger:main Feb 24, 2026
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fix: debug_traceTransaction default param#9788

fix: debug_traceTransaction default param#9788
macfarla merged 10 commits intohyperledger:mainfrom
macfarla:debug-trace-tx-empty-options

macfarla commented Feb 11, 2026 •

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-    assertThat(defaultConfig.traceStorage()).isTrue();
-    assertThat(defaultConfig.traceMemory()).isFalse();
-    assertThat(defaultConfig.traceStack()).isTrue();
+    final OpCodeTracerConfig expectedConfig = OpCodeTracerConfig.DEFAULT;
+    assertThat(defaultConfig.traceStorage()).isEqualTo(expectedConfig.traceStorage());
+    assertThat(defaultConfig.traceMemory()).isEqualTo(expectedConfig.traceMemory());
+    assertThat(defaultConfig.traceStack()).isEqualTo(expectedConfig.traceStack());

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macfarla commented Feb 11, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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PR description

Fixed Issue(s)

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Pull request overview

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macfarla commented Feb 11, 2026 •

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