[ty] Ignore possibly-unresolved-reference by default (#17934)

.github/mypy-primer-ty.toml

@@ -0,0 +1,6 @@
+#:schema ../ty.schema.json
+# Configuration overrides for the mypy primer run
+
+# Enable off-by-default rules.
+[rules]
+possibly-unresolved-reference = "warn"

.github/workflows/mypy_primer.yaml

@@ -50,6 +50,10 @@ jobs:
         run: |
           cd ruff
 
+          echo "Enabling mypy primer specific configuration overloads (see .github/mypy-primer-ty.toml)"
+          mkdir -p ~/.config/ty
+          cp .github/mypy-primer-ty.toml ~/.config/ty/ty.toml
+
           PRIMER_SELECTOR="$(paste -s -d'|' crates/ty_python_semantic/resources/primer/good.txt)"
 
           echo "new commit"

crates/ty/docs/rules.md

@@ -1394,33 +1394,6 @@ or `ImportError` at runtime.
 * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L822)
 </details>
 
-## `possibly-unresolved-reference`
-
-**Default level**: warn
-
-<details>
-<summary>detects references to possibly undefined names</summary>
-
-### What it does
-Checks for references to names that are possibly not defined.
-
-### Why is this bad?
-Using an undefined variable will raise a `NameError` at runtime.
-
-### Example
-
-```python
-for i in range(0):
-    x = i
-
-print(x)  # NameError: name 'x' is not defined
-```
-
-### Links
-* [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unresolved-reference)
-* [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L836)
-</details>
-
 ## `redundant-cast`
 
 **Default level**: warn
@@ -1552,3 +1525,30 @@ a = 20 / 2
 * [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Fsuppression.rs#L15)
 </details>
 
+## `possibly-unresolved-reference`
+
+**Default level**: ignore
+
+<details>
+<summary>detects references to possibly undefined names</summary>
+
+### What it does
+Checks for references to names that are possibly not defined.
+
+### Why is this bad?
+Using an undefined variable will raise a `NameError` at runtime.
+
+### Example
+
+```python
+for i in range(0):
+    x = i
+
+print(x)  # NameError: name 'x' is not defined
+```
+
+### Links
+* [Related issues](https://github.com/astral-sh/ty/issues?q=sort%3Aupdated-desc%20is%3Aissue%20is%3Aopen%20possibly-unresolved-reference)
+* [View source](https://github.com/astral-sh/ruff/blob/main/crates%2Fty_python_semantic%2Fsrc%2Ftypes%2Fdiagnostic.rs#L836)
+</details>
+

crates/ty/tests/cli.rs

@@ -369,12 +369,12 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
             for a in range(0, int(y)):
                 x = a
 
-            print(x)  # possibly-unresolved-reference
+            prin(x)  # unresolved-reference
             "#,
     )?;
 
-    // Assert that there's a possibly unresolved reference diagnostic
+    // Assert that there's an `unresolved-reference` diagnostic (error)
-    // and that division-by-zero has a severity of error by default.
+    // and a `division-by-zero` diagnostic (error).
     assert_cmd_snapshot!(case.command(), @r"
     success: false
     exit_code: 1
@@ -389,15 +389,15 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
       |
     info: `lint:division-by-zero` is enabled by default
 
-    warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    warning: lint:unresolved-reference: Name `prin` used when not defined
-     --> test.py:7:7
+     --> test.py:7:1
       |
     5 |     x = a
     6 |
-    7 | print(x)  # possibly-unresolved-reference
+    7 | prin(x)  # unresolved-reference
-      |       ^
+      | ^^^^
       |
-    info: `lint:possibly-unresolved-reference` is enabled by default
+    info: `lint:unresolved-reference` is enabled by default
 
     Found 2 diagnostics
 
@@ -409,7 +409,7 @@ fn configuration_rule_severity() -> anyhow::Result<()> {
         r#"
         [tool.ty.rules]
         division-by-zero = "warn" # demote to warn
-        possibly-unresolved-reference = "ignore"
+        unresolved-reference = "ignore"
     "#,
     )?;
 
@@ -448,12 +448,12 @@ fn cli_rule_severity() -> anyhow::Result<()> {
         for a in range(0, int(y)):
             x = a
 
-        print(x)  # possibly-unresolved-reference
+        prin(x)  # unresolved-reference
         "#,
     )?;
 
-    // Assert that there's a possibly unresolved reference diagnostic
+    // Assert that there's an `unresolved-reference` diagnostic (error),
-    // and that division-by-zero has a severity of error by default.
+    // a `division-by-zero` (error) and a unresolved-import (error) diagnostic by default.
     assert_cmd_snapshot!(case.command(), @r"
     success: false
     exit_code: 1
@@ -480,15 +480,15 @@ fn cli_rule_severity() -> anyhow::Result<()> {
       |
     info: `lint:division-by-zero` is enabled by default
 
-    warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    warning: lint:unresolved-reference: Name `prin` used when not defined
-     --> test.py:9:7
+     --> test.py:9:1
       |
     7 |     x = a
     8 |
-    9 | print(x)  # possibly-unresolved-reference
+    9 | prin(x)  # unresolved-reference
-      |       ^
+      | ^^^^
       |
-    info: `lint:possibly-unresolved-reference` is enabled by default
+    info: `lint:unresolved-reference` is enabled by default
 
     Found 3 diagnostics
 
@@ -499,7 +499,7 @@ fn cli_rule_severity() -> anyhow::Result<()> {
         case
             .command()
             .arg("--ignore")
-            .arg("possibly-unresolved-reference")
+            .arg("unresolved-reference")
             .arg("--warn")
             .arg("division-by-zero")
             .arg("--warn")
@@ -551,12 +551,12 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
         for a in range(0, int(y)):
             x = a
 
-        print(x)  # possibly-unresolved-reference
+        prin(x)  # unresolved-reference
         "#,
     )?;
 
-    // Assert that there's a possibly unresolved reference diagnostic
+    // Assert that there's a `unresolved-reference` diagnostic (error)
-    // and that division-by-zero has a severity of error by default.
+    // and a `division-by-zero` (error) by default.
     assert_cmd_snapshot!(case.command(), @r"
     success: false
     exit_code: 1
@@ -571,15 +571,15 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
       |
     info: `lint:division-by-zero` is enabled by default
 
-    warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    warning: lint:unresolved-reference: Name `prin` used when not defined
-     --> test.py:7:7
+     --> test.py:7:1
       |
     5 |     x = a
     6 |
-    7 | print(x)  # possibly-unresolved-reference
+    7 | prin(x)  # unresolved-reference
-      |       ^
+      | ^^^^
       |
-    info: `lint:possibly-unresolved-reference` is enabled by default
+    info: `lint:unresolved-reference` is enabled by default
 
     Found 2 diagnostics
 
@@ -590,12 +590,12 @@ fn cli_rule_severity_precedence() -> anyhow::Result<()> {
         case
             .command()
             .arg("--error")
-            .arg("possibly-unresolved-reference")
+            .arg("unresolved-reference")
             .arg("--warn")
             .arg("division-by-zero")
             // Override the error severity with warning
             .arg("--ignore")
-            .arg("possibly-unresolved-reference"),
+            .arg("unresolved-reference"),
         @r"
     success: true
     exit_code: 0
@@ -951,7 +951,7 @@ fn user_configuration() -> anyhow::Result<()> {
             for a in range(0, int(y)):
                 x = a
 
-            print(x)
+            prin(x)
             "#,
         ),
     ])?;
@@ -979,15 +979,15 @@ fn user_configuration() -> anyhow::Result<()> {
       |
     info: `lint:division-by-zero` was selected in the configuration file
 
-    warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    warning: lint:unresolved-reference: Name `prin` used when not defined
-     --> main.py:7:7
+     --> main.py:7:1
       |
     5 |     x = a
     6 |
-    7 | print(x)
+    7 | prin(x)
-      |       ^
+      | ^^^^
       |
-    info: `lint:possibly-unresolved-reference` is enabled by default
+    info: `lint:unresolved-reference` is enabled by default
 
     Found 2 diagnostics
 
@@ -995,7 +995,7 @@ fn user_configuration() -> anyhow::Result<()> {
     "
     );
 
-    // The user-level configuration promotes `possibly-unresolved-reference` to an error.
+    // The user-level configuration sets the severity for `unresolved-reference` to error.
     // Changing the level for `division-by-zero` has no effect, because the project-level configuration
     // has higher precedence.
     case.write_file(
@@ -1003,7 +1003,7 @@ fn user_configuration() -> anyhow::Result<()> {
         r#"
         [rules]
         division-by-zero = "error"
-        possibly-unresolved-reference = "error"
+        unresolved-reference = "error"
         "#,
     )?;
 
@@ -1023,15 +1023,15 @@ fn user_configuration() -> anyhow::Result<()> {
       |
     info: `lint:division-by-zero` was selected in the configuration file
 
-    error: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+    error: lint:unresolved-reference: Name `prin` used when not defined
-     --> main.py:7:7
+     --> main.py:7:1
       |
     5 |     x = a
     6 |
-    7 | print(x)
+    7 | prin(x)
-      |       ^
+      | ^^^^
       |
-    info: `lint:possibly-unresolved-reference` was selected in the configuration file
+    info: `lint:unresolved-reference` was selected in the configuration file
 
     Found 2 diagnostics
 

crates/ty_python_semantic/resources/mdtest/snapshots/for.md_-_For_loops_-_With_non-callable_iterator.snap

@@ -59,7 +59,7 @@ info: revealed-type: Revealed type
 ```
 
 ```
-warning: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
+info: lint:possibly-unresolved-reference: Name `x` used when possibly not defined
   --> src/mdtest_snippet.py:16:17
    |
 14 |     # revealed: Unknown

crates/ty_python_semantic/src/lint.rs

@@ -475,12 +475,26 @@ impl RuleSelection {
     /// Creates a new rule selection from all known lints in the registry that are enabled
     /// according to their default severity.
     pub fn from_registry(registry: &LintRegistry) -> Self {
+        Self::from_registry_with_default(registry, None)
+    }
+
+    /// Creates a new rule selection from all known lints in the registry, including lints that are default by default.
+    /// Lints that are disabled by default use the `default_severity`.
+    pub fn all(registry: &LintRegistry, default_severity: Severity) -> Self {
+        Self::from_registry_with_default(registry, Some(default_severity))
+    }
+
+    fn from_registry_with_default(
+        registry: &LintRegistry,
+        default_severity: Option<Severity>,
+    ) -> Self {
         let lints = registry
             .lints()
             .iter()
             .filter_map(|lint| {
                 Severity::try_from(lint.default_level())
                     .ok()
+                    .or(default_severity)
                     .map(|severity| (*lint, (severity, LintSource::Default)))
             })
             .collect();

crates/ty_python_semantic/src/types/diagnostic.rs

@@ -851,7 +851,7 @@ declare_lint! {
     pub(crate) static POSSIBLY_UNRESOLVED_REFERENCE = {
         summary: "detects references to possibly undefined names",
         status: LintStatus::preview("1.0.0"),
-        default_level: Level::Warn,
+        default_level: Level::Ignore,
     }
 }
 

crates/ty_test/src/db.rs

@@ -1,4 +1,5 @@
 use camino::{Utf8Component, Utf8PathBuf};
+use ruff_db::diagnostic::Severity;
 use ruff_db::files::{File, Files};
 use ruff_db::system::{
     CaseSensitivity, DbWithWritableSystem, InMemorySystem, OsSystem, System, SystemPath,
@@ -25,7 +26,7 @@ pub(crate) struct Db {
 
 impl Db {
     pub(crate) fn setup() -> Self {
-        let rule_selection = RuleSelection::from_registry(default_lint_registry());
+        let rule_selection = RuleSelection::all(default_lint_registry(), Severity::Info);
 
         Self {
             system: MdtestSystem::in_memory(),

ty.schema.json

@@ -653,7 +653,7 @@
         "possibly-unresolved-reference": {
           "title": "detects references to possibly undefined names",
           "description": "## What it does\nChecks for references to names that are possibly not defined.\n\n## Why is this bad?\nUsing an undefined variable will raise a `NameError` at runtime.\n\n## Example\n\n```python\nfor i in range(0):\n    x = i\n\nprint(x)  # NameError: name 'x' is not defined\n```",
-          "default": "warn",
+          "default": "ignore",
           "oneOf": [
             {
               "$ref": "#/definitions/Level"