feat(core): added simple linter for the conjugations of "to be" for #256

harper-core/affixes.json

@@ -483,7 +483,9 @@
       "replacements": [],
       "adds_metadata": {},
       "gifts_metadata": {
-        "noun": {}
+        "noun": {
+          "is_plural": false
+        }
       }
     },
     "2": {
@@ -557,6 +559,17 @@
         }
       }
     },
+    "9": {
+      "suffix": true,
+      "cross_product": true,
+      "replacements": [],
+      "adds_metadata": {},
+      "gifts_metadata": {
+        "noun": {
+          "is_plural": true
+        }
+      }
+    },
     "~": {
       "suffix": true,
       "cross_product": true,

harper-core/dictionary.dict

@@ -45485,7 +45485,7 @@ therapeutically/
 therapeutics/1M
 therapist/1SM
 therapy/14SM
-there/18~
+there/~
 there's/
 thereabout/S
 thereafter/1
@@ -45519,7 +45519,7 @@ thermostatic/5
 thermostatically/
 thesauri/1
 thesaurus/1MS
-these/8S~
+these/8S~9
 thesis/1M
 thespian/51SM
 theta/1SM
@@ -45544,9 +45544,8 @@ thieve/4DSG
 thievery/1M
 thieving/451M
 thievish/5
-thigh/1M
+thigh/1MS
 thighbone/1MS
-thighs/1
 thimble/14MS
 thimbleful/1SM
 thin/514YSP

harper-core/src/linting/lint.rs

@@ -36,6 +36,7 @@ pub enum LintKind {
     Repetition,
     Enhancement,
     Readability,
+    WordChoice,
     #[default]
     Miscellaneous,
 }
@@ -50,6 +51,7 @@ impl Display for LintKind {
             LintKind::Readability => "Readability",
             LintKind::Miscellaneous => "Miscellaneous",
             LintKind::Enhancement => "Enhancement",
+            LintKind::WordChoice => "Word Choice",
         };
 
         write!(f, "{}", s)

harper-core/src/linting/lint_group.rs

@@ -14,6 +14,7 @@ use super::long_sentences::LongSentences;
 use super::matcher::Matcher;
 use super::multiple_sequential_pronouns::MultipleSequentialPronouns;
 use super::number_suffix_capitalization::NumberSuffixCapitalization;
+use super::plural_conjugate::PluralConjugate;
 use super::proper_noun_capitalization_linters::{
     AmazonNames, Americas, AppleNames, AzureNames, ChineseCommunistParty, GoogleNames, Holidays,
     Koreas, MetaNames, MicrosoftNames, UnitedOrganizations,
@@ -173,7 +174,8 @@ create_lint_group_config!(
     MicrosoftNames => true,
     AppleNames => true,
     AzureNames => true,
-    CompoundWords => true
+    CompoundWords => true,
+    PluralConjugate => true
 );
 
 impl<T: Dictionary + Default> Default for LintGroup<T> {

harper-core/src/linting/mod.rs

@@ -14,6 +14,7 @@ mod matcher;
 mod multiple_sequential_pronouns;
 mod number_suffix_capitalization;
 mod pattern_linter;
+mod plural_conjugate;
 mod proper_noun_capitalization_linters;
 mod repeated_words;
 mod sentence_capitalization;
@@ -63,6 +64,7 @@ pub trait Linter {
     fn lint(&mut self, document: &Document) -> Vec<Lint>;
     fn description(&self) -> &str;
 }
+
 #[cfg(feature = "concurrent")]
 pub trait Linter: Send + Sync {
     fn lint(&mut self, document: &Document) -> Vec<Lint>;

harper-core/src/linting/plural_conjugate.rs

@@ -0,0 +1,94 @@
+use crate::{
+    patterns::{EitherPattern, Pattern, SequencePattern},
+    Token,
+};
+
+use super::{Lint, LintKind, PatternLinter, Suggestion};
+
+pub struct PluralConjugate {
+    pattern: Box<dyn Pattern>,
+}
+
+impl Default for PluralConjugate {
+    fn default() -> Self {
+        let plural_case = SequencePattern::default()
+            .then_plural_noun()
+            .then_whitespace()
+            .then_exact_word("is");
+
+        let non_plural_case = SequencePattern::default()
+            .then(Box::new(|tok: &Token, _source: &[char]| {
+                tok.kind.is_not_plural_noun() && tok.kind.is_noun()
+            }))
+            .then_whitespace()
+            .then_exact_word("are");
+
+        let pat = EitherPattern::new(vec![Box::new(plural_case), Box::new(non_plural_case)]);
+
+        Self {
+            pattern: Box::new(pat),
+        }
+    }
+}
+
+impl PatternLinter for PluralConjugate {
+    fn pattern(&self) -> &dyn Pattern {
+        self.pattern.as_ref()
+    }
+
+    fn match_to_lint(&self, matched_tokens: &[Token], _source: &[char]) -> Lint {
+        let should_be_plural = matched_tokens.first().unwrap().kind.is_plural_noun();
+
+        let sug = if should_be_plural {
+            vec!['a', 'r', 'e']
+        } else {
+            vec!['i', 's']
+        };
+
+        Lint {
+            span: matched_tokens.last().unwrap().span,
+            lint_kind: LintKind::WordChoice,
+            suggestions: vec![Suggestion::ReplaceWith(sug)],
+            message: "Use the alternative conjugation of this verb to be consistent with the noun's plural nature.".to_owned(),
+            priority: 63,
+        }
+    }
+
+    fn description(&self) -> &'static str {
+        "Make sure you use the correct conjugation of the verb \"to be\" in plural contexts."
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use crate::linting::tests::assert_suggestion_result;
+
+    use super::PluralConjugate;
+
+    #[test]
+    fn issue_256() {
+        assert_suggestion_result(
+            "The bananas is tasty",
+            PluralConjugate::default(),
+            "The bananas are tasty",
+        );
+    }
+
+    #[test]
+    fn plural_students() {
+        assert_suggestion_result(
+            "The students is doing their homework.",
+            PluralConjugate::default(),
+            "The students are doing their homework.",
+        );
+    }
+
+    #[test]
+    fn singular_house() {
+        assert_suggestion_result(
+            "The house are just sitting there.",
+            PluralConjugate::default(),
+            "The house is just sitting there.",
+        );
+    }
+}

harper-core/src/spell/full_dictionary.rs

@@ -329,4 +329,12 @@ mod tests {
 
         assert!(is_sorted_by_dist)
     }
+
+    #[test]
+    fn there_is_not_a_pronoun() {
+        let dict = FullDictionary::curated();
+
+        assert!(!dict.get_word_metadata_str("there").is_noun());
+        assert!(!dict.get_word_metadata_str("there").is_pronoun_noun());
+    }
 }

harper-core/src/token.rs

@@ -319,6 +319,22 @@ impl TokenKind {
         metadata.is_linking_verb()
     }
 
+    pub fn is_not_plural_noun(&self) -> bool {
+        let TokenKind::Word(metadata) = self else {
+            return true;
+        };
+
+        metadata.is_not_plural_noun()
+    }
+
+    pub fn is_plural_noun(&self) -> bool {
+        let TokenKind::Word(metadata) = self else {
+            return false;
+        };
+
+        metadata.is_plural_noun()
+    }
+
     pub fn is_noun(&self) -> bool {
         let TokenKind::Word(metadata) = self else {
             return false;

harper-core/tests/test_sources/obsidian_links.md

@@ -3,7 +3,7 @@
 Below, you will find a number of example links that Obsidian is able to process.
 
 These should be treated as normal Markdown links.
-The stuff inside the square brackets is visible and should be checked by Harper.
+The things inside the square brackets are visible and should be checked by Harper.
 
 [[Three lws of motion]]
 [Three las of motion](Three%20laws%20of%20motion.md)