test(docs): add tests for examples in website hero and repo README (#2710)

Co-authored-by: Maximilian Roos <[email protected]>

Author: eitsupi

README.md

@@ -31,7 +31,7 @@ filter country == "USA"                       # Each line transforms the previou
 aggregate {                                   # `aggregate` reduces each column to a value
   max salary,
   min salary,
-  count,                                      # Trailing commas are allowed
+  count s"*",                                      # Trailing commas are allowed
 }
 ```
 

prql-compiler/tests/docs/main.rs

@@ -0,0 +1,76 @@
+use prql_compiler::Options;
+use regex::Regex;
+use serde_yaml::Value;
+use std::fs;
+
+const WEBSITE_TOPPAGE: &str = "../web/website/content/_index.md";
+
+fn compile(prql: &str) -> Result<String, prql_compiler::ErrorMessages> {
+    prql_compiler::compile(prql, &Options::default().no_signature())
+}
+
+fn sql_normalize(sql: &str) -> String {
+    let re = Regex::new(r"\n\s+").unwrap();
+    re.replace_all(sql, " ").trim().to_string()
+}
+
+fn website_contents() -> Value {
+    let contents = fs::read_to_string(WEBSITE_TOPPAGE)
+        .unwrap()
+        .replace("---", "");
+
+    serde_yaml::from_str::<Value>(&contents).unwrap()
+}
+
+fn website_examples() -> Vec<Value> {
+    let value = website_contents();
+
+    value
+        .get("showcase_section")
+        .unwrap()
+        .get("examples")
+        .unwrap()
+        .as_sequence()
+        .unwrap()
+        .to_vec()
+}
+
+fn website_hero_example() -> String {
+    let value = website_contents();
+
+    value
+        .get("hero_section")
+        .unwrap()
+        .get("prql_example")
+        .unwrap()
+        .as_str()
+        .unwrap()
+        .to_string()
+}
+
+#[test]
+fn test_readme_examples() {
+    let contents = fs::read_to_string("../README.md").unwrap();
+    // Similar to code at https://github.com/PRQL/prql/blob/65706a115a84997c608eaeda38b1aef1240fcec3/web/book/tests/snapshot.rs#L152, but specialized for the Readme.
+    let re = Regex::new(r"(?s)```(elm|prql)\n(?P<prql>.+?)\n```").unwrap();
+    assert_ne!(re.find_iter(&contents).count(), 0);
+    for cap in re.captures_iter(&contents) {
+        let prql = &cap["prql"];
+        compile(prql).unwrap();
+    }
+}
+
+#[test]
+fn test_website_examples() {
+    for example in website_examples() {
+        let prql = example.get("prql").unwrap().as_str().unwrap();
+        let sql = example.get("sql").unwrap().as_str().unwrap();
+        assert_eq!(sql_normalize(&compile(prql).unwrap()), sql_normalize(sql));
+    }
+}
+
+#[test]
+fn test_website_hero_example() {
+    let prql = website_hero_example();
+    compile(&prql).unwrap();
+}

prql-compiler/tests/website/main.rs

@@ -23,7 +23,7 @@ hero_section:
       aggregate {
         average total,
         sum_income = sum income,
-        ct = count,
+        ct = count s"*",
       }
     )
     sort {-sum_income}