feat(gnovm): add extensible linting framework with AVL001 and GLOBAL001 rules by MikaelVallenet · Pull Request #5068 · gnolang/gno

MikaelVallenet · 2026-01-17T16:18:33Z

Summary (PR description is mostly AI generated and then adapted by me)

This PR adds an extensible linting framework to gno lint. You can now write pluggable rules, choose different
output formats, and suppress warnings with //nolint comments.

What's New

New Lint Package (`gnovm/pkg/lint/`)

Core stuff:

Issue - represents a single lint finding (severity, location, message)
Severity - three levels: info, warning, error
Rule interface - implement this to create your own lint rules
RuleContext - gives rules access to the file, source code, and parent nodes
Registry - handles rule registration (rules self-register via init())
Config - controls mode and which rules to disable
NolintParser - reads //nolint comments to suppress specific issues

Reporters (how output gets formatted):

TextReporter - human-friendly output, sorted by file/line, with a summary at the end
JSONReporter - machine-readable JSON array for tooling integration
DirectReporter - prints issues immediately as they're found (used by gno test)

Built-in rules:

AVL001 - warns when you iterate an entire AVL tree without bounds (tree.Iterate("", "", ...))
GLOBAL001 - warns about exported package-level variables (like var Counter int)

CLI Changes (`gnovm/cmd/gno/lint.go`)

New flags:

--mode - choose between default, strict, or warn-only
--format - output as text or json
--list-rules - shows all available rules and exits
--disable-rules - skip specific rules (e.g., --disable-rules=AVL001,GLOBAL001)

Output format changed:
Before

  file.gno:10:5: some message (code=someCode)

After

  file.gno:10:5: warning: some message (AVL001)

Docs

Added docs/resources/gno-lint.md with usage examples, rule descriptions, and a guide for writing new rules

Tests

Unit tests for everything in gnovm/pkg/lint/
Integration tests (txtar format) covering AVL001, GLOBAL001, nolint directives, and mode flags

Breaking Changes

Output format - The lint output now includes severity and uses a different format (see above)

Exit codes - Now depend on the mode:

Mode	Exits with 1 when...
`default`	there are errors
`strict`	there are any issues (warnings become errors)
`warn-only`	never (errors become warnings)

Gno2D2 · 2026-01-17T16:19:06Z

🛠 PR Checks Summary

All Automated Checks passed. ✅

Manual Checks (for Reviewers):

IGNORE the bot requirements for this PR (force green CI check)

✅ Automated Checks (for Contributors):

🟢 Maintainers must be able to edit this pull request (more info)
🟢 Pending initial approval by a review team member, or review from tech-staff

☑️ Contributor Actions:

Fix any issues flagged by automated checks.
Follow the Contributor Checklist to ensure your PR is ready for review.
- Add new tests, or document why they are unnecessary.
- Provide clear examples/screenshots, if necessary.
- Update documentation, if required.
- Ensure no breaking changes, or include BREAKING CHANGE notes.
- Link related issues/PRs, where applicable.

☑️ Reviewer Actions:

Complete manual checks for the PR, including the guidelines and additional checks if applicable.

📚 Resources:

Debug

Automated Checks

Maintainers must be able to edit this pull request (more info)

If

🟢 Condition met
└── 🟢 And
    ├── 🟢 The base branch matches this pattern: ^master$
    └── 🟢 The pull request was created from a fork (head branch repo: MikaelVallenet/gno)

Then

🟢 Requirement satisfied
└── 🟢 Maintainer can modify this pull request

Pending initial approval by a review team member, or review from tech-staff

If

🟢 Condition met
└── 🟢 And
    ├── 🟢 The base branch matches this pattern: ^master$
    └── 🟢 Not (🔴 Pull request author is a member of the team: tech-staff)

Then

🟢 Requirement satisfied
└── 🟢 If
    ├── 🟢 Condition
    │   └── 🟢 Or
    │       ├── 🟢 User davd-gzl already reviewed PR 5068 with state APPROVED
    │       ├── 🔴 At least 1 user(s) of the team tech-staff reviewed pull request
    │       └── 🔴 This pull request is a draft
    └── 🟢 Then
        └── 🟢 Not (🔴 This label is applied to pull request: review/triage-pending)

Manual Checks

**IGNORE** the bot requirements for this PR (force green CI check)
If
🟢 Condition met
└── 🟢 On every pull request
Can be checked by

Any user with comment edit permission

codecov · 2026-01-17T16:21:29Z

Codecov Report

❌ Patch coverage is 85.74257% with 72 lines in your changes missing coverage. Please review.

Files with missing lines	Patch %	Lines
gnovm/cmd/gno/lint.go	61.76%	21 Missing and 5 partials ⚠️
gnovm/cmd/gno/common.go	60.97%	16 Missing ⚠️
gnovm/pkg/lint/rules/avl001.go	77.04%	9 Missing and 5 partials ⚠️
gnovm/pkg/lint/rules/render001.go	82.97%	8 Missing ⚠️
gnovm/pkg/lint/registry.go	92.59%	2 Missing ⚠️
gnovm/pkg/lint/reporters/direct.go	86.66%	2 Missing ⚠️
gnovm/pkg/lint/rules/global001.go	95.00%	1 Missing and 1 partial ⚠️
gnovm/pkg/lint/severity.go	92.30%	1 Missing and 1 partial ⚠️

📢 Thoughts on this report? Let us know!

davd-gzl

Overall implementations seems working great from my testing, there's some nitpick and code can be simplified at some place but it seems like an efficient V1.
I need to do a second review to be sure!

MikaelVallenet · 2026-02-02T12:59:42Z

docs/resources/gno-lint.md

@@ -0,0 +1,154 @@
+# Gno Lint


MikaelVallenet · 2026-02-02T13:01:41Z

docs/resources/gno-lint.md

+## Command Line Options
+
+| Flag | Default | Description |
+|------|---------|-------------|


davd-gzl · 2026-01-29T16:10:02Z

docs/resources/gno-lint.md

+## Available Rules
+
+- **AVL001** (warning): Unbounded AVL tree iteration - detects `avl.Tree.Iterate()` or `ReverseIterate()` with empty bounds (`"", ""`)
+- **GLOBAL001** (warning): Exported package-level variable - detects exported (uppercase) `var` declarations at package level


This rule is triggered on the variables of the next code snippets, which I don't think should.
If it's possible with the AST you are working with, we would have better to trigger this warning only on dangerous exported variable (e.g.: structure containing public method returning object, not readonly tainted value, whatever else).

package grc1155 import "errors" var ( ErrInvalidAddress = errors.New("invalid address") ErrMismatchLength = errors.New("accounts and ids length mismatch") ErrCannotTransferToSelf = errors.New("cannot send transfer to self") ErrTransferToRejectedOrNonGRC1155Receiver = errors.New("transfer to rejected or non GRC1155Receiver implementer") ErrCallerIsNotOwnerOrApproved = errors.New("caller is not token owner or approved") ErrInsufficientBalance = errors.New("insufficient balance for transfer") ErrBurnAmountExceedsBalance = errors.New("burn amount exceeds balance") ErrInvalidAmount = errors.New("invalid amount") )

davd@davd ~/P/g/e/g/p/d/t/grc1155 (mikael/experiment/linter-archi)> gno lint . errors.gno:6:2: warning: exported package-level variable: ErrInvalidAddress (GLOBAL001) errors.gno:7:2: warning: exported package-level variable: ErrMismatchLength (GLOBAL001) errors.gno:8:2: warning: exported package-level variable: ErrCannotTransferToSelf (GLOBAL001) errors.gno:9:2: warning: exported package-level variable: ErrTransferToRejectedOrNonGRC1155Receiver (GLOBAL001) errors.gno:10:2: warning: exported package-level variable: ErrCallerIsNotOwnerOrApproved (GLOBAL001) errors.gno:11:2: warning: exported package-level variable: ErrInsufficientBalance (GLOBAL001) errors.gno:12:2: warning: exported package-level variable: ErrBurnAmountExceedsBalance (GLOBAL001) errors.gno:13:2: warning: exported package-level variable: ErrInvalidAmount (GLOBAL001) Found 8 issue(s): 0 error(s), 8 warning(s), 0 info

what about using the // nolint directive for these one
it's a way to acknowledge you know what you do IMO
will fix the others reviews asap

I don't think it's a good idea, it's gonna pollute the code base especially if we have to refactor everything.
I feel we would have better to set it deactivated by default with a warning on that flag, fix the flag with only problematic global variable, or remove it entirely as the false positive will be too high.

davd-gzl · 2026-01-29T16:13:25Z

docs/resources/gno-lint.md

+    return false
+})
+
+//nolint:GLOBAL001


It would be great to be able to inline this comment (or add an example if it's already implemented)

var Config = DefaultConfig() //nolint:GLOBAL001

Out of scope IMO can be done in another PR

davd-gzl · 2026-01-29T19:13:53Z

gnovm/pkg/lint/reporters/json.go

+
+	r.issues = append(r.issues, issue)
+
+	switch issue.Severity {


This is duplicated

text and json implementations shared some common business logic, we could use a common base but i don't think it make sense here, just for 2 implem. can you developp your thinking

This specific switch case is duplicated 4 times and is related to a constant behavior, I think this should be moved in a generic helper.
The sort function from the flush too, but I agree we don't have to use a common base in that case.

MikaelVallenet · 2026-02-02T13:12:38Z

gnovm/pkg/lint/reporter.go

+// to allow reuse by other commands (run, test) without coupling them to the lint package.
+type Reporter interface {
+	Report(issue Issue)
+	Flush() error


moonia

Overall, LGTM.
The implementation appears to be working as expected based on my testing. As Davphla mentioned, it might be worth adding this to docs/README.md

thehowl · 2026-02-03T13:42:28Z

I'll review this when I can; can you make sure to include the additions you made in #4943 as well? :)

davd-gzl

I tested every features, it all works great except the edge case of avl001

davd-gzl · 2026-02-06T11:44:15Z

gnovm/pkg/lint/reporters/json.go

+
+	r.issues = append(r.issues, issue)
+
+	switch issue.Severity {


This specific switch case is duplicated 4 times and is related to a constant behavior, I think this should be moved in a generic helper.
The sort function from the flush too, but I agree we don't have to use a common base in that case.

davd-gzl · 2026-02-06T12:03:42Z

gnovm/pkg/lint/rules/avl001.go

+	}
+}
+
+func (AVL001) Check(ctx *lint.RuleContext, node gnolang.Node) []lint.Issue {


For some reason this rule is not triggered on examples/gno.land/p/demo/microblog/microblog.gno:L39

fixed: f0e468e

jefft0 · 2026-03-19T09:50:56Z

@MikaelVallenet , the failed Lint CI check for "images/manifesto/boards2.jpeg" has been fixed in master. If you merge master again, then it should fix this CI check.

github-project-automation bot added this to 💪 Bounties & Worx and 🧙‍♂️Gno.land development Jan 17, 2026

github-project-automation bot moved this to Triage in 🧙‍♂️Gno.land development Jan 17, 2026

github-actions bot assigned MikaelVallenet Jan 17, 2026

github-actions bot added 📖 documentation Improvements or additions to documentation 📦 🤖 gnovm Issues or PRs gnovm related labels Jan 17, 2026

Gno2D2 requested a review from a team January 17, 2026 16:19

MikaelVallenet mentioned this pull request Jan 19, 2026

feat(lint): poc 2.0 linter gno handle extensions rules #4940

Closed

MikaelVallenet marked this pull request as ready for review January 20, 2026 13:10

MikaelVallenet requested review from davd-gzl and moonia January 20, 2026 13:10

Gno2D2 added the review/triage-pending PRs opened by external contributors that are waiting for the 1st review label Jan 20, 2026

MikaelVallenet mentioned this pull request Jan 21, 2026

fix(govdao): make Tiers private to prevent external modification #5075

Merged

jefft0 added this to the ⏭️Next after mainnet beta milestone Jan 28, 2026

Kouteki moved this from Triage to In Review in 🧙‍♂️Gno.land development Jan 28, 2026

Kouteki removed the request for review from a team January 28, 2026 21:58

davd-gzl reviewed Jan 29, 2026

View reviewed changes

Gno2D2 requested a review from a team January 29, 2026 19:26

moonia approved these changes Feb 2, 2026

View reviewed changes

jefft0 moved this to Other dev assigned in 🤝🏻 Partner: Berty Feb 4, 2026

jefft0 added this to 🤝🏻 Partner: Berty Feb 4, 2026

davd-gzl approved these changes Feb 6, 2026

View reviewed changes

Kouteki requested review from notJoon and thehowl and removed request for a team February 15, 2026 22:04

jaekwon force-pushed the master branch from 8759cbe to 6545790 Compare February 24, 2026 01:38

MikaelVallenet force-pushed the mikael/experiment/linter-archi branch from fdbe30b to b954995 Compare March 10, 2026 13:33

MikaelVallenet added 13 commits March 10, 2026 14:39

feat(lint): docs & tests

77c5f22

feat(lint): docs & tests

e402af6

feat(lint): docs & tests

c86f8d3

feat(lint): docs & tests

a6c8d6e

feat(lint): docs & tests

36b5163

feat(lint): docs & tests

8a248df

feat(lint): docs & tests

69060a0

feat(lint): docs & tests

2e7dcae

feat(lint): clean code & merge gno code issue & lint issues

baf0ce0

docs(lint): add gno lint docs entry in docs/readme

c470b01

docs(lint): add all flags in the doc

bb26133

feat(lint): reset reporter after flush

3dde708

docs(lint): add gno lint docs entry in docs/readme

484d008

MikaelVallenet force-pushed the mikael/experiment/linter-archi branch from b954995 to 484d008 Compare March 10, 2026 13:40

MikaelVallenet added 8 commits March 10, 2026 15:50

feat(lint): implement render signature lint rule using new framework

e5b8057

feat(lint): improve proposal

f0e468e

Merge branch 'master' into mikael/experiment/linter-archi

682189f

feat(lint): improve proposal

4b6bb9e

feat(lint): improve proposal

d3ae4bc

feat(lint): improve proposal

872a4a0

Merge branch 'master' into mikael/experiment/linter-archi

642b28c

Merge branch 'master' into mikael/experiment/linter-archi

4b06485

MikaelVallenet added 3 commits March 19, 2026 11:00

Merge branch 'master' into mikael/experiment/linter-archi

86a2dac

Merge branch 'master' into mikael/experiment/linter-archi

6705934

Merge branch 'master' into mikael/experiment/linter-archi

c22560d

davd-gzl mentioned this pull request Mar 26, 2026

fix(gnoland): prevent duplicate validator removals in EndBlocker #5356

Open

3 tasks

Merge branch 'master' into mikael/experiment/linter-archi

bf970ab

Gno2D2 removed the review/triage-pending PRs opened by external contributors that are waiting for the 1st review label Mar 26, 2026

Merge branch 'master' into mikael/experiment/linter-archi

fe6cb10

Conversation

MikaelVallenet commented Jan 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary (PR description is mostly AI generated and then adapted by me)

What's New

New Lint Package (gnovm/pkg/lint/)

CLI Changes (gnovm/cmd/gno/lint.go)

Docs

Tests

Breaking Changes

Uh oh!

Gno2D2 commented Jan 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

🛠 PR Checks Summary

Manual Checks (for Reviewers):

✅ Automated Checks (for Contributors):

☑️ Contributor Actions:

☑️ Reviewer Actions:

📚 Resources:

If

Then

If

Then

If

Can be checked by

Uh oh!

codecov bot commented Jan 17, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Codecov Report

Uh oh!

davd-gzl left a comment • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

This comment was marked as resolved.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

This comment was marked as resolved.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

davd-gzl Feb 6, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

MikaelVallenet Feb 2, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

This comment was marked as resolved.

Uh oh!

Choose a reason for hiding this comment

Uh oh!

moonia left a comment

Choose a reason for hiding this comment

Uh oh!

thehowl commented Feb 3, 2026

Uh oh!

davd-gzl left a comment

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

Choose a reason for hiding this comment

Uh oh!

MikaelVallenet commented Jan 17, 2026 •

edited

Loading

New Lint Package (`gnovm/pkg/lint/`)

CLI Changes (`gnovm/cmd/gno/lint.go`)

Gno2D2 commented Jan 17, 2026 •

edited

Loading

codecov bot commented Jan 17, 2026 •

edited

Loading

davd-gzl left a comment •

edited

Loading

davd-gzl Feb 6, 2026 •

edited

Loading

MikaelVallenet Feb 2, 2026 •

edited

Loading