Merge branch 'main' into exhaustive-deps

CHANGELOG.md

@@ -14,6 +14,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Excludes are now respected for single files.
 - Added `no-exclude` cli flag to disable excludes.
 - When given in standard library format, additional information now shows up in `incorrect_standard_library_use` missing required parameter errors.
+- Added new [`mixed_table` lint](https://kampfkarren.github.io/selene/lints/mixed_table.html), which will warn against mixed tables.
 
 ### Fixed
 - `string.pack` and `string.unpack` now have proper function signatures in the Lua 5.3 standard library.

docs/src/SUMMARY.md

@@ -27,6 +27,7 @@
   - [incorrect_standard_library_use](./lints/incorrect_standard_library_use.md)
   - [manual_table_clone](./lints/manual_table_clone.md)
   - [mismatched_arg_count](./lints/mismatched_arg_count.md)
+  - [mixed_table](./lints/mixed_table.md)
   - [multiple_statements](./lints/multiple_statements.md)
   - [must_use](./lints/must_use.md)
   - [parenthese_conditions](./lints/parenthese_conditions.md)

docs/src/contributing.md

@@ -130,7 +130,7 @@ The first `"cool_lint"` is the name of the folder we created. The second `"cool_
 
 Now, just run `cargo test`, and a `.stderr` file will be automatically generated! You can manipulate it however you see fit as well as modifying your lint, and so long as the file is there, selene will make sure that its accurate.
 
-Optionally, you can add a `.std.toml` with the same name as the test next to the lua file, where you can specify a custom [standard library](./usage/std.html) to use. If you do not, the Lua 5.1 standard library will be used.
+Optionally, you can add a `.std.toml` with the same name as the test next to the lua file, where you can specify a custom [standard library](./usage/std.md) to use. If you do not, the Lua 5.1 standard library will be used.
 
 ### Documenting it
 

docs/src/lints/mixed_table.md

@@ -0,0 +1,14 @@
+# mixed_table
+## What it does
+Checks for mixed tables (tables that act as both an array and dictionary).
+
+## Why this is bad
+Mixed tables harms readability and are prone to bugs. There is almost always a better alternative.
+
+## Example
+```lua
+local foo = {
+    "array field",
+    bar = "dictionary field",
+}
+```

docs/src/roblox.md

@@ -2,7 +2,7 @@
 
 selene is built with Roblox development in mind, and has special features for Roblox developers.
 
-If you try to run selene on a Roblox codebase, you'll get a bunch of errors saying things such as "`game` is not defined". This is because these are Roblox specific globals that selene does not know about. You'll need to install the Roblox [standard library](./usage/configuration) in order to fix these issues, as well as get Roblox specific lints.
+If you try to run selene on a Roblox codebase, you'll get a bunch of errors saying things such as "`game` is not defined". This is because these are Roblox specific globals that selene does not know about. You'll need to install the Roblox [standard library](./usage/configuration.md) in order to fix these issues, as well as get Roblox specific lints.
 
 ## Installation
 

selene-lib/src/lib.rs

@@ -312,6 +312,7 @@ use_lints! {
     invalid_lint_filter: lints::invalid_lint_filter::InvalidLintFilterLint,
     manual_table_clone: lints::manual_table_clone::ManualTableCloneLint,
     mismatched_arg_count: lints::mismatched_arg_count::MismatchedArgCountLint,
+    mixed_table: lints::mixed_table::MixedTableLint,
     multiple_statements: lints::multiple_statements::MultipleStatementsLint,
     must_use: lints::must_use::MustUseLint,
     parenthese_conditions: lints::parenthese_conditions::ParentheseConditionsLint,

selene-lib/src/lints.rs

@@ -23,6 +23,7 @@ pub mod ifs_same_cond;
 pub mod invalid_lint_filter;
 pub mod manual_table_clone;
 pub mod mismatched_arg_count;
+pub mod mixed_table;
 pub mod multiple_statements;
 pub mod must_use;
 pub mod parenthese_conditions;

selene-lib/src/lints/mixed_table.rs

@@ -0,0 +1,92 @@
+use super::*;
+use crate::ast_util::range;
+use std::convert::Infallible;
+
+use full_moon::{
+    ast::{self, Ast},
+    visitors::Visitor,
+};
+
+pub struct MixedTableLint;
+
+impl Lint for MixedTableLint {
+    type Config = ();
+    type Error = Infallible;
+
+    const SEVERITY: Severity = Severity::Warning;
+    const LINT_TYPE: LintType = LintType::Correctness;
+
+    fn new(_: Self::Config) -> Result<Self, Self::Error> {
+        Ok(MixedTableLint)
+    }
+
+    fn pass(&self, ast: &Ast, _: &Context, _: &AstContext) -> Vec<Diagnostic> {
+        let mut visitor = MixedTableVisitor::default();
+
+        visitor.visit_ast(ast);
+
+        let mut diagnostics = Vec::new();
+
+        for mixed_table in visitor.mixed_tables {
+            diagnostics.push(Diagnostic::new_complete(
+                "mixed_table",
+                "mixed tables are not allowed".to_owned(),
+                Label::new(mixed_table.range),
+                vec!["help: change this table to either an array or dictionary".to_owned()],
+                Vec::new(),
+            ));
+        }
+
+        diagnostics
+    }
+}
+
+#[derive(Default)]
+struct MixedTableVisitor {
+    mixed_tables: Vec<MixedTable>,
+}
+
+struct MixedTable {
+    range: (usize, usize),
+}
+
+impl Visitor for MixedTableVisitor {
+    fn visit_table_constructor(&mut self, node: &ast::TableConstructor) {
+        let mut last_key_field_starting_range = 0;
+        let mut last_no_key_field_starting_range = 0;
+
+        for field in node.fields() {
+            if let ast::Field::NoKey(_) = field {
+                if last_key_field_starting_range > 0 {
+                    self.mixed_tables.push(MixedTable {
+                        range: (last_key_field_starting_range, range(field).1),
+                    });
+                    return;
+                }
+                last_no_key_field_starting_range = range(field).0;
+            } else {
+                if last_no_key_field_starting_range > 0 {
+                    self.mixed_tables.push(MixedTable {
+                        range: (last_no_key_field_starting_range, range(field).1),
+                    });
+                    return;
+                }
+                last_key_field_starting_range = range(field).0;
+            }
+        }
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use super::{super::test_util::test_lint, *};
+
+    #[test]
+    fn test_mixed_table() {
+        test_lint(
+            MixedTableLint::new(()).unwrap(),
+            "mixed_table",
+            "mixed_table",
+        );
+    }
+}

selene-lib/tests/lints/mixed_table/mixed_table.lua

@@ -0,0 +1,53 @@
+local bad = {
+    "",
+    a = b,
+}
+
+bad = {
+    {},
+    [a] = b,
+}
+
+bad = {
+    a,
+    [""] = b,
+}
+
+-- This is technically not a mixed table, but it's formatted like it harming readability
+-- so it should still be linted
+bad = {
+    1,
+    [2] = b,
+}
+
+bad = {
+    [a] = b,
+    [c] = d,
+    "",
+}
+
+bad({
+    a = b,
+    "",
+    c = d,
+})
+
+local good = {
+    a = b,
+    c = d,
+}
+
+good = {
+    "",
+    a,
+}
+
+good = {
+    [1] = a,
+    [3] = b,
+}
+
+good({
+    a = b,
+    c = d,
+})

selene-lib/tests/lints/mixed_table/mixed_table.stderr

@@ -0,0 +1,54 @@
+error[mixed_table]: mixed tables are not allowed
+  ┌─ mixed_table.lua:2:5
+  │  
+2 │ ╭     "",
+3 │ │     a = b,
+  │ ╰─────────^
+  │  
+  = help: change this table to either an array or dictionary
+
+error[mixed_table]: mixed tables are not allowed
+  ┌─ mixed_table.lua:7:5
+  │  
+7 │ ╭     {},
+8 │ │     [a] = b,
+  │ ╰───────────^
+  │  
+  = help: change this table to either an array or dictionary
+
+error[mixed_table]: mixed tables are not allowed
+   ┌─ mixed_table.lua:12:5
+   │  
+12 │ ╭     a,
+13 │ │     [""] = b,
+   │ ╰────────────^
+   │  
+   = help: change this table to either an array or dictionary
+
+error[mixed_table]: mixed tables are not allowed
+   ┌─ mixed_table.lua:19:5
+   │  
+19 │ ╭     1,
+20 │ │     [2] = b,
+   │ ╰───────────^
+   │  
+   = help: change this table to either an array or dictionary
+
+error[mixed_table]: mixed tables are not allowed
+   ┌─ mixed_table.lua:25:5
+   │  
+25 │ ╭     [c] = d,
+26 │ │     "",
+   │ ╰──────^
+   │  
+   = help: change this table to either an array or dictionary
+
+error[mixed_table]: mixed tables are not allowed
+   ┌─ mixed_table.lua:30:5
+   │  
+30 │ ╭     a = b,
+31 │ │     "",
+   │ ╰──────^
+   │  
+   = help: change this table to either an array or dictionary
+