2 files changed, 84 insertions, 0 deletions
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
index 1d04b72..481d99e 100644
--- a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/RustWriterTests.java
@@ -564,6 +564,45 @@ public class RustWriterTests {
         assertThat(string, equalTo("f(x, y)"));
     }
 
+    // === Closure expressions ===
+
+    @Test
+    public void closureExpressionWithNoParams() throws IOException {
+        var rust = RustClosureExpression.arbitrary()
+            .withBody(RustPath.of("a"))
+            .build();
+
+        var string = write(writer -> writer.writeTopLevelExpression(rust));
+
+        assertThat(string, equalTo("|| a"));
+    }
+
+    @Test
+    public void closureExpressionWithOneParam() throws IOException {
+        var rust = RustClosureExpression.arbitrary()
+            .addParam(RustIdentifierPattern.arbitrary().withVariableName(RustIdentifier.of("a")))
+            .withBody(RustPath.of("a"))
+            .build();
+
+        var string = write(writer -> writer.writeTopLevelExpression(rust));
+
+        assertThat(string, equalTo("|a| a"));
+    }
+
+    @Test
+    public void closureExpressionWithMultipleParams() throws IOException {
+        var rust = RustClosureExpression.arbitrary()
+            .addParam(RustIdentifierPattern.arbitrary().withVariableName(RustIdentifier.of("a")))
+            .addParam(RustIdentifierPattern.arbitrary().withVariableName(RustIdentifier.of("b")))
+            .addParam(RustIdentifierPattern.arbitrary().withVariableName(RustIdentifier.of("c")))
+            .withBody(RustPath.of("a"))
+            .build();
+
+        var string = write(writer -> writer.writeTopLevelExpression(rust));
+
+        assertThat(string, equalTo("|a, b, c| a"));
+    }
+
     // === Field expressions ===
 
     @Test
diff --git a/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustClosureExpressionMatcher.java b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustClosureExpressionMatcher.java
new file mode 100644
index 0000000..d50cc13
--- /dev/null
+++ b/src/test/java/org/zwobble/hobgoblin/compiler/output/lang/rust/ast/RustClosureExpressionMatcher.java
@@ -0,0 +1,45 @@
+// Generated by hobgoblin.
+
+package org.zwobble.hobgoblin.compiler.output.lang.rust.ast;
+
+// Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher imports
+// Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher imports
+
+public class RustClosureExpressionMatcher implements org.zwobble.precisely.Matcher<java.lang.Object> {
+    public static org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher isRustClosureExpression() {
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher(java.util.List.of());
+    }
+
+    private final java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpression>> submatchers;
+
+    private RustClosureExpressionMatcher(java.util.List<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpression>> submatchers) {
+        this.submatchers = submatchers;
+    }
+
+    public org.zwobble.precisely.MatchResult match(java.lang.Object actual) {
+        return this.toMatcher().match(actual);
+    }
+
+    public org.zwobble.precisely.TextTree describe() {
+        return this.toMatcher().describe();
+    }
+
+    private org.zwobble.precisely.Matcher<java.lang.Object> toMatcher() {
+        return org.zwobble.precisely.Matchers.instanceOf(org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpression.class, this.submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher withParams(org.zwobble.precisely.Matcher<? super java.util.List<org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustPattern>> params) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpression>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("params", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpression::params, params));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher(submatchers);
+    }
+
+    public org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher withBody(org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustExpression> body) {
+        var submatchers = new java.util.ArrayList<org.zwobble.precisely.Matcher<? super org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpression>>(this.submatchers);
+        submatchers.add(org.zwobble.precisely.Matchers.has("body", org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpression::body, body));
+        return new org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher(submatchers);
+    }
+
+    // Custom area start: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher body
+    // Custom area end: org.zwobble.hobgoblin.compiler.output.lang.rust.ast.RustClosureExpressionMatcher body
+}