Add tests for DayPeirod AmPm and NoonMidnight patterns

- Restructures `format` module to use directory structure instead of single file.
- Adds a `format/tests` directory.
- Moves existing local tests from `format.rs` to `format/tests/mod.rs`
- Adds JSON test data for `DayPeriod` patterns.
- Adds JSON-serializable structs for testing formatting patterns.
- Adds test cases for `DayPeriod` patterns.
- Adds parsing test cases for the `b` `DayPeriod` pattern.

components/datetime/src/format.rs → components/datetime/src/format/mod.rs

@@ -1,6 +1,9 @@
 // This file is part of ICU4X. For terms of use, please see the file
 // called LICENSE at the top level of the ICU4X source tree
 // (online at: https://github.com/unicode-org/icu4x/blob/master/LICENSE ).
+#[cfg(test)]
+mod tests;
+
 use crate::date::{self, DateTimeType};
 use crate::error::DateTimeFormatError;
 use crate::fields::{self, FieldLength, FieldSymbol};
@@ -144,39 +147,17 @@ where
                     format_number(w, date_time.second().into(), field.length)?
                 }
                 FieldSymbol::DayPeriod(period) => {
-                    let symbol =
-                        data.get_symbol_for_day_period(period, field.length, date_time.hour(), date_time.minute());
+                    let symbol = data.get_symbol_for_day_period(
+                        period,
+                        field.length,
+                        date_time.hour(),
+                        date_time.minute(),
+                    );
                     w.write_str(symbol)?
-                },
+                }
             },
             PatternItem::Literal(l) => w.write_str(l)?,
         }
     }
     Ok(())
 }
-
-#[cfg(test)]
-mod tests {
-    use super::*;
-
-    #[test]
-    fn test_format_numer() {
-        let values = &[2, 20, 201, 2017, 20173];
-        let samples = &[
-            (FieldLength::One, ["2", "20", "201", "2017", "20173"]),
-            (FieldLength::TwoDigit, ["02", "20", "01", "17", "73"]),
-            (
-                FieldLength::Abbreviated,
-                ["002", "020", "201", "2017", "20173"],
-            ),
-            (FieldLength::Wide, ["0002", "0020", "0201", "2017", "20173"]),
-        ];
-        for (length, expected) in samples {
-            for (value, expected) in values.iter().zip(expected) {
-                let mut s = String::new();
-                format_number(&mut s, *value, *length).unwrap();
-                assert_eq!(s, *expected);
-            }
-        }
-    }
-}

components/datetime/src/format/tests/mod.rs

@@ -0,0 +1,76 @@
+// This file is part of ICU4X. For terms of use, please see the file
+// called LICENSE at the top level of the ICU4X source tree
+// (online at: https://github.com/unicode-org/icu4x/blob/master/LICENSE ).
+mod patterns;
+
+use super::{format_number, write_pattern};
+use crate::{date::MockDateTime, fields::FieldLength, pattern::Pattern};
+use icu_locid::LanguageIdentifier;
+use icu_provider::{
+    structs::{self, dates::gregory::DatesV1},
+    DataProvider, DataRequest, ResourceOptions, ResourcePath,
+};
+use std::borrow::Cow;
+
+#[test]
+fn test_format_numer() {
+    let values = &[2, 20, 201, 2017, 20173];
+    let samples = &[
+        (FieldLength::One, ["2", "20", "201", "2017", "20173"]),
+        (FieldLength::TwoDigit, ["02", "20", "01", "17", "73"]),
+        (
+            FieldLength::Abbreviated,
+            ["002", "020", "201", "2017", "20173"],
+        ),
+        (FieldLength::Wide, ["0002", "0020", "0201", "2017", "20173"]),
+    ];
+    for (length, expected) in samples {
+        for (value, expected) in values.iter().zip(expected) {
+            let mut s = String::new();
+            format_number(&mut s, *value, *length).unwrap();
+            assert_eq!(s, *expected);
+        }
+    }
+}
+
+#[test]
+fn test_format_patterns() {
+    use patterns::structs::Expectation;
+    let provider = icu_testdata::get_provider();
+    for test in patterns::get_tests("dayperiods").unwrap().0 {
+        let langid: LanguageIdentifier = test.locale.parse().unwrap();
+        let data: Cow<DatesV1> = provider
+            .load_payload(&DataRequest {
+                resource_path: ResourcePath {
+                    key: structs::dates::key::GREGORY_V1,
+                    options: ResourceOptions {
+                        variant: None,
+                        langid: Some(langid.clone()),
+                    },
+                },
+            })
+            .unwrap()
+            .take_payload()
+            .unwrap();
+        for test_case in &test.test_cases {
+            for dt_input in &test_case.date_times {
+                let date_time: MockDateTime = dt_input.parse().unwrap();
+                for Expectation { patterns, expected } in &test_case.expectations {
+                    for pattern_input in patterns {
+                        let pattern = Pattern::from_bytes(pattern_input).unwrap();
+                        let mut actual = String::with_capacity(expected.len());
+                        write_pattern(&pattern, &data, &date_time, &mut actual).unwrap();
+                        assert_eq!(
+                            actual, *expected,
+                            "\n\
+                            locale:   `{}`,\n\
+                            datetime: `{}`,\n\
+                            pattern:  `{}`",
+                            langid, dt_input, pattern_input,
+                        );
+                    }
+                }
+            }
+        }
+    }
+}

components/datetime/src/format/tests/patterns/mod.rs

@@ -0,0 +1,13 @@
+// This file is part of ICU4X. For terms of use, please see the file
+// called LICENSE at the top level of the ICU4X source tree
+// (online at: https://github.com/unicode-org/icu4x/blob/master/LICENSE ).
+pub mod structs;
+
+use std::fs::File;
+use std::io::BufReader;
+
+pub fn get_tests(name: &str) -> std::io::Result<structs::Tests> {
+    let file = File::open(format!("./src/format/tests/patterns/tests/{}.json", name))?;
+    let reader = BufReader::new(file);
+    Ok(serde_json::from_reader(reader)?)
+}

components/datetime/src/format/tests/patterns/structs.rs

@@ -0,0 +1,25 @@
+// This file is part of ICU4X. For terms of use, please see the file
+// called LICENSE at the top level of the ICU4X source tree
+// (online at: https://github.com/unicode-org/icu4x/blob/master/LICENSE ).
+use serde::{Deserialize, Serialize};
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct Tests(pub Vec<Test>);
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct Test {
+    pub locale: String,
+    pub test_cases: Vec<TestCase>,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct TestCase {
+    pub date_times: Vec<String>,
+    pub expectations: Vec<Expectation>,
+}
+
+#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
+pub struct Expectation {
+    pub patterns: Vec<String>,
+    pub expected: String,
+}