fix: redundant-none-rule #324

wdl-lint/src/rules.rs

@@ -33,6 +33,7 @@ mod pascal_case;
 mod preamble_comment_after_version;
 mod preamble_formatting;
 mod redundant_input_assignment;
+mod redundant_none;
 mod runtime_section_keys;
 mod section_order;
 mod shellcheck;
@@ -76,6 +77,7 @@ pub use pascal_case::*;
 pub use preamble_comment_after_version::*;
 pub use preamble_formatting::*;
 pub use redundant_input_assignment::*;
+pub use redundant_none::*;
 pub use runtime_section_keys::*;
 pub use section_order::*;
 pub use shellcheck::*;

wdl-lint/src/rules/redundant_none.rs

@@ -0,0 +1,99 @@
+use crate::Rule;
+use crate::Tag;
+use crate::TagSet;
+use std::fmt::Debug;
+use wdl_ast::AstToken;
+use wdl_ast::Diagnostic;
+use wdl_ast::Diagnostics;
+use wdl_ast::Document;
+use wdl_ast::Span;
+use wdl_ast::SupportedVersion;
+use wdl_ast::SyntaxElement;
+use wdl_ast::VisitReason;
+use wdl_ast::Visitor;
+use wdl_ast::v1::InputSection;
+
+const ID: &str = "RedundantNoneAssignment";
+
+fn redundant_none_assignment(span: Span, name: &str) -> Diagnostic {
+    Diagnostic::note("redundant None assignment")
+        .with_rule(ID)
+        .with_highlight(span)
+        .with_fix(format!("can be shortened to {}", name))
+}
+
+#[derive(Default, Debug, Clone, Copy)]
+pub struct RedundantNoneAssignment;
+
+impl Rule for RedundantNoneAssignment {
+    fn id(&self) -> &'static str {
+        ID
+    }
+
+    fn description(&self) -> &'static str {
+        "Flags redundant None assignments to optional inputs."
+    }
+
+    fn explanation(&self) -> &'static str {
+        "Optional inputs with explicit None assignments can be simplified. For example, \
+         String? foo = None can be shortened to String? foo."
+    }
+
+    fn tags(&self) -> TagSet {
+        TagSet::new(&[Tag::Clarity])
+    }
+
+    fn exceptable_nodes(&self) -> Option<&'static [wdl_ast::SyntaxKind]> {
+        Some(&[
+            wdl_ast::SyntaxKind::VersionStatementNode,
+            wdl_ast::SyntaxKind::InputSectionNode,
+            wdl_ast::SyntaxKind::BoundDeclNode,
+        ])
+    }
+}
+
+impl Visitor for RedundantNoneAssignment {
+    type State = Diagnostics;
+
+    fn document(
+        &mut self,
+        _: &mut Self::State,
+        reason: VisitReason,
+        _: &Document,
+        version: SupportedVersion,
+    ) {
+        if reason == VisitReason::Exit {
+            return;
+        }
+        *self = Default::default();
+    }
+
+    fn input_section(
+        &mut self,
+        state: &mut Self::State,
+        reason: VisitReason,
+        section: &InputSection,
+    ) {
+        if reason == VisitReason::Exit {
+            return;
+        }
+        section.declarations().for_each(|decl| {
+            if let token = decl.ty() {
+                if token.is_optional() {
+                    if let Some(expr) = decl.expr() {
+                        if let Some(name_ref) = expr.as_literal().unwrap().as_none() {
+                            let text_range = decl.syntax().text_range();
+                            let span =
+                                Span::from(text_range.start().into()..text_range.end().into());
+                            state.exceptable_add(
+                                redundant_none_assignment(span, decl.name().as_str()),
+                                SyntaxElement::from(decl.syntax().clone()),
+                                &self.exceptable_nodes(),
+                            );
+                        }
+                    }
+                }
+            }
+        });
+    }
+}

wdl-lint/tests/lints/redudant-none/source.errors

@@ -0,0 +1,42 @@
+note[CallInputSpacing]: call input not properly spaced
+   ┌─ tests/lints/redudant-none/source.wdl:16:21
+   │  
+16 │       call test_task {
+   │ ╭────────────────────^
+17 │ │         input:
+   │ ╰────────^
+   │  
+   = fix: change this whitespace to a single space
+
+warning[MissingRuntime]: task `test_task` is missing a `runtime` section
+   ┌─ tests/lints/redudant-none/source.wdl:23:6
+   │
+23 │ task test_task {
+   │      ^^^^^^^^^ this task is missing a `runtime` section
+   │
+   = fix: add a `runtime` section
+
+note[Whitespace]: line contains only whitespace
+   ┌─ tests/lints/redudant-none/source.wdl:31:1
+   │
+31 │     
+   │ ^^^^
+   │
+   = fix: remove the whitespace
+
+note[Whitespace]: line contains only whitespace
+   ┌─ tests/lints/redudant-none/source.wdl:35:1
+   │
+35 │     
+   │ ^^^^
+   │
+   = fix: remove the whitespace
+
+note[EndingNewline]: missing newline at the end of the file
+   ┌─ tests/lints/redudant-none/source.wdl:39:1
+   │
+39 │ }
+   │ ^ expected a newline to follow this
+   │
+   = fix: add a newline at the end of the file
+

wdl-lint/tests/lints/redudant-none/source.wdl

@@ -0,0 +1,39 @@
+#@ except: DescriptionMissing, MissingRequirements
+#@ except: RuntimeSectionKeys, MissingMetas, MissingOutput
+
+version 1.0
+
+workflow redundant_none_test {
+    input {
+        String required_str
+        Int? optional_int  # should not flag, correct optional syntax
+        String? optional_str = None  # should flag, redundant None for optional
+        Float? optional_float = 3.14  # should not flag, has non-None default
+        Int required_int = 5  # should not flag
+    }
+
+    # Test in a task context as well
+    call test_task {
+        input:
+            req_param = required_str,
+            opt_param = optional_str,
+    }
+}
+
+task test_task {
+    input {
+        String req_param
+        Int? opt_int  # should not flag
+        File? opt_file = None  # should not flag due to except directive
+        String? opt_param = None  # should flag, redundant None
+        Boolean? opt_bool = true  # should not flag, has non-None default
+    }
+
+    command <<<
+        echo "Testing redundant None detection"
+    >>>
+
+    output {
+        String result = "done"
+    }
+}