Move fixtures to a separate file

1 files changed, 288 insertions, 0 deletions

diff --git a/crates/test_utils/src/fixture.rs b/crates/test_utils/src/fixture.rs
new file mode 100644
index 000000000..d0a732031
--- /dev/null
+++ b/crates/test_utils/src/fixture.rs
@@ -0,0 +1,288 @@
+use ra_cfg::CfgOptions;
+use rustc_hash::FxHashMap;
+use stdx::split1;
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct FixtureEntry {
+    pub meta: FixtureMeta,
+    pub text: String,
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub enum FixtureMeta {
+    Root { path: String },
+    File(FileMeta),
+}
+
+#[derive(Debug, Eq, PartialEq)]
+pub struct FileMeta {
+    pub path: String,
+    pub crate_name: Option<String>,
+    pub deps: Vec<String>,
+    pub cfg: CfgOptions,
+    pub edition: Option<String>,
+    pub env: FxHashMap<String, String>,
+}
+
+impl FixtureMeta {
+    pub fn path(&self) -> &str {
+        match self {
+            FixtureMeta::Root { path } => &path,
+            FixtureMeta::File(f) => &f.path,
+        }
+    }
+
+    pub fn crate_name(&self) -> Option<&String> {
+        match self {
+            FixtureMeta::File(f) => f.crate_name.as_ref(),
+            _ => None,
+        }
+    }
+
+    pub fn cfg_options(&self) -> Option<&CfgOptions> {
+        match self {
+            FixtureMeta::File(f) => Some(&f.cfg),
+            _ => None,
+        }
+    }
+
+    pub fn edition(&self) -> Option<&String> {
+        match self {
+            FixtureMeta::File(f) => f.edition.as_ref(),
+            _ => None,
+        }
+    }
+
+    pub fn env(&self) -> impl Iterator<Item = (&String, &String)> {
+        struct EnvIter<'a> {
+            iter: Option<std::collections::hash_map::Iter<'a, String, String>>,
+        }
+
+        impl<'a> EnvIter<'a> {
+            fn new(meta: &'a FixtureMeta) -> Self {
+                Self {
+                    iter: match meta {
+                        FixtureMeta::File(f) => Some(f.env.iter()),
+                        _ => None,
+                    },
+                }
+            }
+        }
+
+        impl<'a> Iterator for EnvIter<'a> {
+            type Item = (&'a String, &'a String);
+            fn next(&mut self) -> Option<Self::Item> {
+                self.iter.as_mut().and_then(|i| i.next())
+            }
+        }
+
+        EnvIter::new(self)
+    }
+}
+
+/// Same as `parse_fixture`, except it allow empty fixture
+pub fn parse_single_fixture(ra_fixture: &str) -> Option<FixtureEntry> {
+    if !ra_fixture.lines().any(|it| it.trim_start().starts_with("//-")) {
+        return None;
+    }
+
+    let fixtures = parse_fixture(ra_fixture);
+    if fixtures.len() > 1 {
+        panic!("too many fixtures");
+    }
+    fixtures.into_iter().nth(0)
+}
+
+/// Parses text which looks like this:
+///
+///  ```not_rust
+///  //- some meta
+///  line 1
+///  line 2
+///  // - other meta
+///  ```
+pub fn parse_fixture(ra_fixture: &str) -> Vec<FixtureEntry> {
+    let fixture = indent_first_line(ra_fixture);
+    let margin = fixture_margin(&fixture);
+
+    let mut lines = fixture
+        .split('\n') // don't use `.lines` to not drop `\r\n`
+        .enumerate()
+        .filter_map(|(ix, line)| {
+            if line.len() >= margin {
+                assert!(line[..margin].trim().is_empty());
+                let line_content = &line[margin..];
+                if !line_content.starts_with("//-") {
+                    assert!(
+                        !line_content.contains("//-"),
+                        r#"Metadata line {} has invalid indentation. All metadata lines need to have the same indentation.
+The offending line: {:?}"#,
+                        ix,
+                        line
+                    );
+                }
+                Some(line_content)
+            } else {
+                assert!(line.trim().is_empty());
+                None
+            }
+        });
+
+    let mut res: Vec<FixtureEntry> = Vec::new();
+    for line in lines.by_ref() {
+        if line.starts_with("//-") {
+            let meta = line["//-".len()..].trim().to_string();
+            let meta = parse_meta(&meta);
+            res.push(FixtureEntry { meta, text: String::new() })
+        } else if let Some(entry) = res.last_mut() {
+            entry.text.push_str(line);
+            entry.text.push('\n');
+        }
+    }
+    res
+}
+
+//- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b env:OUTDIR=path/to,OTHER=foo
+fn parse_meta(meta: &str) -> FixtureMeta {
+    let components = meta.split_ascii_whitespace().collect::<Vec<_>>();
+
+    if components[0] == "root" {
+        let path = components[1].to_string();
+        assert!(path.starts_with("/") && path.ends_with("/"));
+        return FixtureMeta::Root { path };
+    }
+
+    let path = components[0].to_string();
+    assert!(path.starts_with("/"));
+
+    let mut krate = None;
+    let mut deps = Vec::new();
+    let mut edition = None;
+    let mut cfg = CfgOptions::default();
+    let mut env = FxHashMap::default();
+    for component in components[1..].iter() {
+        let (key, value) = split1(component, ':').unwrap();
+        match key {
+            "crate" => krate = Some(value.to_string()),
+            "deps" => deps = value.split(',').map(|it| it.to_string()).collect(),
+            "edition" => edition = Some(value.to_string()),
+            "cfg" => {
+                for key in value.split(',') {
+                    match split1(key, '=') {
+                        None => cfg.insert_atom(key.into()),
+                        Some((k, v)) => cfg.insert_key_value(k.into(), v.into()),
+                    }
+                }
+            }
+            "env" => {
+                for key in value.split(',') {
+                    if let Some((k, v)) = split1(key, '=') {
+                        env.insert(k.into(), v.into());
+                    }
+                }
+            }
+            _ => panic!("bad component: {:?}", component),
+        }
+    }
+
+    FixtureMeta::File(FileMeta { path, crate_name: krate, deps, edition, cfg, env })
+}
+
+/// Adjusts the indentation of the first line to the minimum indentation of the rest of the lines.
+/// This allows fixtures to start off in a different indentation, e.g. to align the first line with
+/// the other lines visually:
+/// ```
+/// let fixture = "//- /lib.rs
+///                mod foo;
+///                //- /foo.rs
+///                fn bar() {}
+/// ";
+/// assert_eq!(fixture_margin(fixture),
+/// "               //- /lib.rs
+///                mod foo;
+///                //- /foo.rs
+///                fn bar() {}
+/// ")
+/// ```
+fn indent_first_line(fixture: &str) -> String {
+    if fixture.is_empty() {
+        return String::new();
+    }
+    let mut lines = fixture.lines();
+    let first_line = lines.next().unwrap();
+    if first_line.contains("//-") {
+        let rest = lines.collect::<Vec<_>>().join("\n");
+        let fixed_margin = fixture_margin(&rest);
+        let fixed_indent = fixed_margin - indent_len(first_line);
+        format!("\n{}{}\n{}", " ".repeat(fixed_indent), first_line, rest)
+    } else {
+        fixture.to_owned()
+    }
+}
+
+fn fixture_margin(fixture: &str) -> usize {
+    fixture
+        .lines()
+        .filter(|it| it.trim_start().starts_with("//-"))
+        .map(indent_len)
+        .next()
+        .expect("empty fixture")
+}
+
+fn indent_len(s: &str) -> usize {
+    s.len() - s.trim_start().len()
+}
+
+#[test]
+#[should_panic]
+fn parse_fixture_checks_further_indented_metadata() {
+    parse_fixture(
+        r"
+        //- /lib.rs
+          mod bar;
+
+          fn foo() {}
+          //- /bar.rs
+          pub fn baz() {}
+          ",
+    );
+}
+
+#[test]
+fn parse_fixture_can_handle_dedented_first_line() {
+    let fixture = "//- /lib.rs
+                   mod foo;
+                   //- /foo.rs
+                   struct Bar;
+";
+    assert_eq!(
+        parse_fixture(fixture),
+        parse_fixture(
+            "//- /lib.rs
+mod foo;
+//- /foo.rs
+struct Bar;
+"
+        )
+    )
+}
+
+#[test]
+fn parse_fixture_gets_full_meta() {
+    let parsed = parse_fixture(
+        r"
+    //- /lib.rs crate:foo deps:bar,baz cfg:foo=a,bar=b,atom env:OUTDIR=path/to,OTHER=foo
+    mod m;
+    ",
+    );
+    assert_eq!(1, parsed.len());
+
+    let parsed = &parsed[0];
+    assert_eq!("mod m;\n\n", parsed.text);
+
+    let meta = &parsed.meta;
+    assert_eq!("foo", meta.crate_name().unwrap());
+    assert_eq!("/lib.rs", meta.path());
+    assert!(meta.cfg_options().is_some());
+    assert_eq!(2, meta.env().count());
+}