mvnlog: build log viewer, integration tests, script routing by gnodet · Pull Request #12699 · apache/maven

gnodet · 2026-08-07T21:32:47Z

Summary

Part 5 of the logging feature chain. Depends on #12698 (warning mode).

Adds the mvnlog tool — a CLI viewer for build-report JSON files — plus integration tests for the entire feature set and script routing.

mvnlog viewer

mvnlog / mvnlog --json — view the latest build report as human-readable or raw JSON
BuildReportRenderer — renders reports with ANSI colors, timing, failure details
SimpleJsonReader — dependency-free streaming JSON parser
LogInvoker / LogParser / LogContext — invoker chain for the tool
CommonsCliLogOptions / LogOptions — CLI option parsing
MavenLogCling — entry point class

Script routing

mvn --log routes to MavenLogCling (both mvn and mvn.cmd)
Script argument stripping prevents --log from colliding with --log-file prefix matching
mvnlog / mvnlog.cmd shell scripts for direct invocation
component.xml updated to include mvnlog in the distribution

Integration tests

MavenITgh12571BuildReportTest — 8 IT tests covering build report JSON, console modes (plain/machine/verbose), warning mode, version info on failure, and mvnlog viewer
11 existing ITs updated with --console=verbose to preserve expected output format
IT test resources (single module + multi-module project POMs)

Files changed (36 files, ~2500 insertions)

Area	Files
API	`Tools.java`, `LogOptions`, `ParserRequest`
Entry point	`MavenLogCling`
Invoker	`LogInvoker`, `LogParser`, `LogContext`, `CommonsCliLogOptions`
Renderer	`BuildReportRenderer`, `SimpleJsonReader`
Shell	`BuiltinShellCommandRegistryFactory` (mvnlog command)
Scripts	`mvn`, `mvn.cmd`, `mvnlog`, `mvnlog.cmd`, `component.xml`
CLI	`CommonsCliOptions` (+`--log` constant/option)
Tests	`BuildReportRendererTest`, `SimpleJsonReaderTest`
ITs	`MavenITgh12571BuildReportTest` + 11 existing ITs + 4 resource POMs

PR chain

#	PR	Feature
1	#12694	Logging foundation
2	#12695	Build report
3	#12697	Console modes
4	#12698	Warning mode + diagnostics
5	This PR	`mvnlog` viewer
6	#12702	Structured problems pipeline
7	#12714	TRACE level migration

Test plan

mvn compile — clean compile
mvn test -pl impl/maven-cli — all tests pass
CI validation

🤖 Generated with Claude Code

- mvnlog / mvnlog --json CLI viewer for build-report JSON files - BuildReportRenderer with ANSI colors, timing, failure details - SimpleJsonReader dependency-free streaming JSON parser - mvn --log routes to MavenLogCling, mvnlog shell scripts - MavenITgh12571BuildReportTest: 8 ITs covering build report, console modes, warning mode, version info on failure, and mvnlog viewer

gnodet

Well-structured mvnlog tool that follows established Maven tool patterns. Two minor polish items noted after verification (three other findings about shell script flag stripping and JSON parser depth were false positives).

Also noted:

The zero-dependency JSON reader/writer approach is sound — no JSON library exists in maven-cli's dependency tree.
The 11 existing IT modifications adding --console=verbose are necessary for the new console mode system.
Strong test coverage with 12 integration test cases.

This review was generated by an AI agent and may contain inaccuracies. Please verify all suggestions before applying.

Claude Code on behalf of gnodet

gnodet · 2026-08-09T08:39:59Z

+            }
+        }
+
+        private List<Completer> mvnlogCompleter(String name) {


The tab-completer only offers --diagnostics, --failures, --full, --list but is missing 5 of the 9 supported options: --json, --module, --mojo, --level, --grep. This reduces discoverability in mvnsh.

Suggested change

private List<Completer> mvnlogCompleter(String name) {

private List<Completer> mvnlogCompleter(String name) {

return List.of(new ArgumentCompleter(new StringsCompleter(

"--diagnostics", "--failures", "--full", "--list", "--json",

"--module", "--mojo", "--level", "--grep")));

gnodet

Well-structured addition of the mvnlog viewer tool that follows established Maven tool patterns. Two minor polish items:

Confirmed findings (verified independently):

[Medium — Dead code] BuildReportRenderer.java:51 — Unused constant MAX_PADDED_BUILD_TIME_DURATION_LENGTH is declared but never referenced anywhere in the class. The formatDuration method does not use it. Appears to be a leftover copy from ExecutionEventLogger where it is actively used.
[Low — Incomplete shell completer] BuiltinShellCommandRegistryFactory.java:268 — The mvnlogCompleter only includes --diagnostics, --failures, --full, --list but is missing the 5 filter/output options defined in CommonsCliLogOptions.CLIManager: --json, --module, --mojo, --level, --grep. Users in mvnsh will not get tab completion for these valid options.

This review was generated by an AI agent (Claude Code) and may contain inaccuracies. Please verify all suggestions before applying.

Claude Code on behalf of Guillaume Nodet

gnodet · 2026-08-16T20:26:29Z

+    private final Consumer<String> output;
+
+    public BuildReportRenderer(MessageBuilderFactory messageBuilderFactory, Consumer<String> output) {
+        this.messageBuilderFactory = messageBuilderFactory;


[Medium — Dead code] This constant is declared but never referenced anywhere in this class. It's actively used in ExecutionEventLogger (lines 61 and 272), but appears to be a copy-paste leftover here.

gnodet · 2026-08-16T20:26:30Z

+                        ParserRequest.mvnlog(input.args(), shellContext.invokerRequest.messageBuilderFactory())
+                                .cwd(shellContext.cwd.get())
+                                .build()));
+            } catch (InvokerException.ExitException e) {


[Low — Incomplete completer] This completer only includes 4 of the 9 options defined in CommonsCliLogOptions.CLIManager. Missing: --json, --module, --mojo, --level, --grep.

Users in mvnsh won't get tab completion for the filter features.

…12702

…#12694

gnodet mentioned this pull request Aug 7, 2026

Build report, console modes, and warning control #12572

Closed

gnodet force-pushed the feature/warning-mode branch from 0cc76eb to 6124231 Compare August 8, 2026 01:23

gnodet force-pushed the feature/mvnlog branch from e89c4e9 to e741028 Compare August 8, 2026 01:23

gnodet force-pushed the feature/mvnlog branch from e741028 to ed79eea Compare August 8, 2026 05:35

gnodet force-pushed the feature/warning-mode branch 2 times, most recently from dc3bccd to a7c83db Compare August 8, 2026 12:14

gnodet force-pushed the feature/mvnlog branch from ed79eea to 8f829c0 Compare August 8, 2026 12:14

gnodet force-pushed the feature/warning-mode branch from a7c83db to 7243fd7 Compare August 8, 2026 19:17

gnodet force-pushed the feature/mvnlog branch from 8f829c0 to ce16de4 Compare August 8, 2026 19:17

gnodet force-pushed the feature/warning-mode branch from 7243fd7 to af945c2 Compare August 8, 2026 19:35

gnodet force-pushed the feature/mvnlog branch from ce16de4 to 7010176 Compare August 8, 2026 19:35

gnodet force-pushed the feature/warning-mode branch from af945c2 to 850a04c Compare August 8, 2026 21:48

gnodet force-pushed the feature/mvnlog branch 2 times, most recently from 9924a43 to 4d7e49f Compare August 8, 2026 21:57

gnodet mentioned this pull request Aug 9, 2026

Migrate internal plumbing DEBUG statements to TRACE level #12714

Open

4 tasks

gnodet force-pushed the feature/warning-mode branch from 850a04c to 5913a2b Compare August 9, 2026 08:11

gnodet force-pushed the feature/mvnlog branch from 4d7e49f to d76d6c1 Compare August 9, 2026 08:11

gnodet marked this pull request as ready for review August 9, 2026 08:11

gnodet commented Aug 9, 2026

View reviewed changes

gnodet mentioned this pull request Aug 9, 2026

#12572 introduced mvnlog #12716

Open

gnodet commented Aug 16, 2026

View reviewed changes

gnodet added a commit to gnodet/maven that referenced this pull request Aug 16, 2026

Update STATE.md — run 8: reviewed apache#12698, apache#12699, apache#…

333137c

…12702

gnodet added a commit to gnodet/maven that referenced this pull request Aug 17, 2026

Update STATE.md — run 11: reviewed apache#12699, apache#12707, apache…

86f976b

…#12694

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mvnlog: build log viewer, integration tests, script routing - #12699

mvnlog: build log viewer, integration tests, script routing#12699
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-        private List<Completer> mvnlogCompleter(String name) {
+        private List<Completer> mvnlogCompleter(String name) {
+            return List.of(new ArgumentCompleter(new StringsCompleter(
+                    "--diagnostics", "--failures", "--full", "--list", "--json",
+                    "--module", "--mojo", "--level", "--grep")));

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gnodet commented Aug 7, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

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Summary

mvnlog viewer

Script routing

Integration tests

Files changed (36 files, ~2500 insertions)

PR chain

Test plan

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gnodet commented Aug 7, 2026 •

edited

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