feat(core): detect improper contraction usage before verbs

harper-core/dictionary.dict

@@ -47557,6 +47557,7 @@ usurp/4SDRZG
 usurpation/1M
 usurper/1M
 usury/1M
+us/8
 utensil/1SM
 uteri/1
 uterine/51

harper-core/src/linting/let_us_redundancy.rs → harper-core/src/linting/lets_confusion/let_us_redundancy.rs

@@ -1,9 +1,9 @@
 use crate::{
-    patterns::{Pattern, SequencePattern, WordSet},
+    patterns::{Pattern, SequencePattern},
     Token, TokenStringExt,
 };
 
-use super::{Lint, LintKind, PatternLinter, Suggestion};
+use crate::linting::{Lint, LintKind, PatternLinter, Suggestion};
 
 pub struct LetUsRedundancy {
     pattern: Box<dyn Pattern>,
@@ -13,7 +13,7 @@ impl Default for LetUsRedundancy {
     fn default() -> Self {
         let pattern = SequencePattern::aco("let's")
             .then_whitespace()
-            .then_word_set(WordSet::all(&["us", "me"]));
+            .then_pronoun();
 
         Self {
             pattern: Box::new(pattern),
@@ -41,15 +41,3 @@ impl PatternLinter for LetUsRedundancy {
         "Many are not aware that the contraction `let's` is short for `let us`. As a result, many will incorrectly use it before a pronoun, such as in the phrase `let's us do`."
     }
 }
-
-#[cfg(test)]
-mod tests {
-    use crate::linting::tests::assert_suggestion_result;
-
-    use super::LetUsRedundancy;
-
-    #[test]
-    fn issue_426() {
-        assert_suggestion_result("let's us do", LetUsRedundancy::default(), "let's do");
-    }
-}

harper-core/src/linting/lets_confusion/mod.rs

@@ -0,0 +1,30 @@
+mod let_us_redundancy;
+mod no_contraction_with_verb;
+
+use super::merge_linters::merge_linters;
+use let_us_redundancy::LetUsRedundancy;
+use no_contraction_with_verb::NoContractionWithVerb;
+
+merge_linters!(LetsConfusion => LetUsRedundancy, NoContractionWithVerb => "TODO");
+
+#[cfg(test)]
+mod tests {
+    use crate::linting::tests::assert_suggestion_result;
+
+    use super::LetsConfusion;
+
+    #[test]
+    fn issue_426_us() {
+        assert_suggestion_result("let's us do", LetsConfusion::default(), "let's do");
+    }
+
+    #[test]
+    fn issue_426_me() {
+        assert_suggestion_result("let's me do", LetsConfusion::default(), "let's do");
+    }
+
+    #[test]
+    fn from_harper_docs() {
+        assert_suggestion_result("Often the longest and the shortest words are the most helpful, so lets push them first.", LetsConfusion::default(), "Often the longest and the shortest words are the most helpful, so let's push them first.");
+    }
+}

harper-core/src/linting/lets_confusion/no_contraction_with_verb.rs

@@ -0,0 +1,47 @@
+use crate::{
+    linting::{Lint, LintKind, Suggestion},
+    patterns::{Pattern, SequencePattern},
+    Token,
+};
+
+use crate::linting::PatternLinter;
+
+pub struct NoContractionWithVerb {
+    pattern: Box<dyn Pattern>,
+}
+
+impl Default for NoContractionWithVerb {
+    fn default() -> Self {
+        let pattern = SequencePattern::aco("lets").then_whitespace().then_verb();
+
+        Self {
+            pattern: Box::new(pattern),
+        }
+    }
+}
+
+impl PatternLinter for NoContractionWithVerb {
+    fn pattern(&self) -> &dyn Pattern {
+        self.pattern.as_ref()
+    }
+
+    fn match_to_lint(&self, matched_tokens: &[Token], source: &[char]) -> Lint {
+        let problem_span = matched_tokens.first().unwrap().span;
+        let template = problem_span.get_content(source);
+
+        Lint {
+            span: problem_span,
+            lint_kind: LintKind::WordChoice,
+            suggestions: vec![
+                Suggestion::replace_with_match_case_str("let's", template),
+                Suggestion::replace_with_match_case_str("let us", template),
+            ],
+            message: "It seems you forgot to include a subject here.".to_owned(),
+            priority: 31,
+        }
+    }
+
+    fn description(&self) -> &'static str {
+        "Make sure you include a subject."
+    }
+}

harper-core/src/linting/lint_group.rs

@@ -8,7 +8,7 @@ use super::capitalize_personal_pronouns::CapitalizePersonalPronouns;
 use super::correct_number_suffix::CorrectNumberSuffix;
 use super::dot_initialisms::DotInitialisms;
 use super::ellipsis_length::EllipsisLength;
-use super::let_us_redundancy::LetUsRedundancy;
+use super::lets_confusion::LetsConfusion;
 use super::linking_verbs::LinkingVerbs;
 use super::long_sentences::LongSentences;
 use super::matcher::Matcher;
@@ -190,8 +190,8 @@ create_lint_group_config!(
     OxfordComma => true,
     PronounContraction => true,
     CurrencyPlacement => true,
-    LetUsRedundancy => true,
-    SomewhatSomething => true
+    SomewhatSomething => true,
+    LetsConfusion => true
 );
 
 impl<T: Dictionary + Default> Default for LintGroup<T> {

harper-core/src/linting/mod.rs

@@ -7,7 +7,7 @@ mod currency_placement;
 mod dashes;
 mod dot_initialisms;
 mod ellipsis_length;
-mod let_us_redundancy;
+mod lets_confusion;
 mod linking_verbs;
 mod lint;
 mod lint_group;
@@ -42,7 +42,7 @@ pub use correct_number_suffix::CorrectNumberSuffix;
 pub use currency_placement::CurrencyPlacement;
 pub use dot_initialisms::DotInitialisms;
 pub use ellipsis_length::EllipsisLength;
-pub use let_us_redundancy::LetUsRedundancy;
+pub use lets_confusion::LetsConfusion;
 pub use linking_verbs::LinkingVerbs;
 pub use lint::{Lint, LintKind, Suggestion};
 pub use lint_group::{LintGroup, LintGroupConfig};

harper-core/tests/run_tests.rs

@@ -48,6 +48,7 @@ create_test!(amazon_hostname.md, 0);
 create_test!(issue_159.md, 1);
 create_test!(issue_358.md, 0);
 create_test!(issue_195.md, 0);
+create_test!(pr_452.md, 2);
 
 // Make sure it doesn't panic
 create_test!(lukas_homework.md, 3);

harper-core/tests/test_sources/pr_452.md

@@ -0,0 +1 @@
+Lets go and check if this lint let's us catch this class of errors.