use crate::validators::{ValidationReport, ValidationResult, Validator};
use polars::prelude::*;
use regex::Regex;
pub struct PatternValidator {
pub pattern: String,
}
impl Validator for PatternValidator {
fn name(&self) -> &'static str {
"Pattern"
}
fn validate(&self, df: &DataFrame, column_name: &str) -> ValidationResult<ValidationReport> {
let series = df.column(column_name)?;
let re = Regex::new(&self.pattern)?;
if let Ok(utf8_chunked) = series.str() {
let bad_count = utf8_chunked
.into_iter()
.filter(|opt_val| {
if let Some(val) = opt_val {
!re.is_match(val)
} else {
false }
})
.count();
if bad_count > 0 {
Ok(ValidationReport {
status: "fail",
details: Some(format!("bad_count={}, pattern={}", bad_count, self.pattern)),
})
} else {
Ok(ValidationReport {
status: "pass",
details: None,
})
}
} else {
Ok(ValidationReport {
status: "skipped",
details: Some("column is not a string type".to_string()),
})
}
}
}
#[cfg(test)]
mod tests {
use super::*;
fn make_str_df(values: &[Option<&str>]) -> DataFrame {
let s = Series::new("col".into(), values.to_vec());
DataFrame::new(vec![s.into()]).unwrap()
}
fn make_int_df(values: &[i32]) -> DataFrame {
let s = Series::new("col".into(), values.to_vec());
DataFrame::new(vec![s.into()]).unwrap()
}
#[test]
fn passes_when_all_values_match_pattern() {
let df = make_str_df(&[Some("abc"), Some("abd"), Some("abe")]);
let validator = PatternValidator {
pattern: r"^ab.$".to_string(),
};
let report = validator.validate(&df, "col").unwrap();
assert_eq!(report.status, "pass");
assert!(report.details.is_none());
}
#[test]
fn fails_when_some_values_do_not_match_pattern() {
let df = make_str_df(&[Some("abc"), Some("xyz"), Some("abd")]);
let validator = PatternValidator {
pattern: r"^ab.$".to_string(),
};
let report = validator.validate(&df, "col").unwrap();
assert_eq!(report.status, "fail");
assert!(report.details.unwrap().contains("bad_count=1"));
}
#[test]
fn ignores_null_values() {
let df = make_str_df(&[Some("abc"), None, Some("abd")]);
let validator = PatternValidator {
pattern: r"^ab.$".to_string(),
};
let report = validator.validate(&df, "col").unwrap();
assert_eq!(report.status, "pass");
}
#[test]
fn passes_on_empty_column() {
let s: Series = Series::new("col".into(), Vec::<Option<&str>>::new());
let df = DataFrame::new(vec![s.into()]).unwrap();
let validator = PatternValidator {
pattern: r"^ab.$".to_string(),
};
let report = validator.validate(&df, "col").unwrap();
assert_eq!(report.status, "pass");
}
#[test]
fn skips_on_non_string_column() {
let df = make_int_df(&[1, 2, 3]);
let validator = PatternValidator {
pattern: r"^ab.$".to_string(),
};
let report = validator.validate(&df, "col").unwrap();
assert_eq!(report.status, "skipped");
assert!(report.details.unwrap().contains("not a string"));
}
}