rename completion -> ide_completion

We don't have completion-related PRs in flight, so lets do it

crates/ide_completion/src/completions/snippet.rs

@@ -0,0 +1,116 @@
+//! This file provides snippet completions, like `pd` => `eprintln!(...)`.
+
+use ide_db::helpers::SnippetCap;
+
+use crate::{
+    item::Builder, CompletionContext, CompletionItem, CompletionItemKind, CompletionKind,
+    Completions,
+};
+
+fn snippet(ctx: &CompletionContext, cap: SnippetCap, label: &str, snippet: &str) -> Builder {
+    CompletionItem::new(CompletionKind::Snippet, ctx.source_range(), label)
+        .insert_snippet(cap, snippet)
+        .kind(CompletionItemKind::Snippet)
+}
+
+pub(crate) fn complete_expr_snippet(acc: &mut Completions, ctx: &CompletionContext) {
+    if !(ctx.is_trivial_path && ctx.function_syntax.is_some()) {
+        return;
+    }
+    let cap = match ctx.config.snippet_cap {
+        Some(it) => it,
+        None => return,
+    };
+
+    snippet(ctx, cap, "pd", "eprintln!(\"$0 = {:?}\", $0);").add_to(acc);
+    snippet(ctx, cap, "ppd", "eprintln!(\"$0 = {:#?}\", $0);").add_to(acc);
+}
+
+pub(crate) fn complete_item_snippet(acc: &mut Completions, ctx: &CompletionContext) {
+    if !ctx.is_new_item {
+        return;
+    }
+    let cap = match ctx.config.snippet_cap {
+        Some(it) => it,
+        None => return,
+    };
+
+    snippet(
+        ctx,
+        cap,
+        "tmod (Test module)",
+        "\
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn ${1:test_name}() {
+        $0
+    }
+}",
+    )
+    .lookup_by("tmod")
+    .add_to(acc);
+
+    snippet(
+        ctx,
+        cap,
+        "tfn (Test function)",
+        "\
+#[test]
+fn ${1:feature}() {
+    $0
+}",
+    )
+    .lookup_by("tfn")
+    .add_to(acc);
+
+    snippet(ctx, cap, "macro_rules", "macro_rules! $1 {\n\t($2) => {\n\t\t$0\n\t};\n}").add_to(acc);
+}
+
+#[cfg(test)]
+mod tests {
+    use expect_test::{expect, Expect};
+
+    use crate::{test_utils::completion_list, CompletionKind};
+
+    fn check(ra_fixture: &str, expect: Expect) {
+        let actual = completion_list(ra_fixture, CompletionKind::Snippet);
+        expect.assert_eq(&actual)
+    }
+
+    #[test]
+    fn completes_snippets_in_expressions() {
+        check(
+            r#"fn foo(x: i32) { $0 }"#,
+            expect![[r#"
+                sn pd
+                sn ppd
+            "#]],
+        );
+    }
+
+    #[test]
+    fn should_not_complete_snippets_in_path() {
+        check(r#"fn foo(x: i32) { ::foo$0 }"#, expect![[""]]);
+        check(r#"fn foo(x: i32) { ::$0 }"#, expect![[""]]);
+    }
+
+    #[test]
+    fn completes_snippets_in_items() {
+        check(
+            r#"
+#[cfg(test)]
+mod tests {
+    $0
+}
+"#,
+            expect![[r#"
+                sn tmod (Test module)
+                sn tfn (Test function)
+                sn macro_rules
+            "#]],
+        )
+    }
+}