[fine] Many test improvements, error improvements

- Check for more error conditions
- Move to more definitive error assertions
- Simpler error messages in some cases
- Test more conditions more thoroughly, revisit old tests

fine/tests/expression/errors/assignment_errors.fine

@@ -14,7 +14,7 @@ fun wrong() {
 }
 
 // @expect-errors:
-// | 7:4: cannot assign a value of type `string` to type `f64`
-// | 8:4: cannot assign a value of type `f64` to type `string`
-// | 11:4: cannot assign a value of type `f64` to type `string`
+// | 7:4: cannot assign a value of type 'string' to type 'f64'
+// | 8:4: cannot assign a value of type 'f64' to type 'string'
+// | 11:4: cannot assign a value of type 'f64' to type 'string'
 // | 13:2: cannot assign a new value to a function declaration

fine/tests/expression/errors/class_as_a_variable.fine

@@ -0,0 +1,8 @@
+class Foo {}
+
+fun test() -> f64 {
+  Foo + 23
+}
+
+// @expect-errors:
+// | 4:2: Foo is a class, not a value (did you mean to create a new instance with 'new'?)

fine/tests/expression/errors/class_duplicate_fields.fine

@@ -3,6 +3,5 @@ class Foo {
   x: f64;
 }
 
-// @ignore
 // @expect-errors:
-// asdfadsf
+// | 3:2: duplicate definition of field 'x'

fine/tests/expression/errors/duplicate_arguments.fine

@@ -1,5 +1,4 @@
 fun something(x: f64, x: f64) {}
 
-// @ignore
 // @expect-errors:
-// asdfadsf
+// | 1:22: duplicate definition of parameter 'x'

fine/tests/expression/errors/duplicates.fine

@@ -0,0 +1,16 @@
+fun nested() {
+  fun foo() {}
+  fun foo() {}
+
+  ;
+}
+
+fun nested() {}
+
+class Bar {}
+class Bar {}
+
+// @expect-errors:
+// | 3:2: duplicate definition of function 'foo'
+// | 8:0: duplicate definition of function 'nested'
+// | 11:0: duplicate definition of class 'Bar'

fine/tests/expression/errors/if_mismatched_arms.fine

@@ -1,2 +1,4 @@
 if true { "blarg" } else { 23 }
-// @type-error: 0 the type of the `then` branch (string) must match the type of the `else` branch (f64)
+
+// @expect-errors:
+// | 1:0: the type of the 'then' branch ('string') must match the type of the 'else' branch ('f64')

fine/tests/expression/errors/if_requires_else.fine

@@ -1,2 +1,4 @@
 if (if false { true }) { 32 } else { 23 }
-// @type-error: 4 the type of the `then` branch (bool) must match the type of the `else` branch (())
+
+// @expect-errors:
+// | 1:4: the type of the 'then' branch ('bool') must match the type of the 'else' branch ('()')

fine/tests/expression/errors/locals_in_globals.fine

@@ -0,0 +1,12 @@
+{
+  // This is a block-local declaration; it should *not* appear in the global
+  // environment.
+  let y = 23;
+}
+
+fun foo() -> f64 {
+  y + 3
+}
+
+// @expect-errors:
+// | 8:2: cannot find value y here

fine/tests/expression/errors/return_statement_mismatch.fine

@@ -5,4 +5,5 @@ fun test() -> f64 {
   23.0
 }
 
-// @check-error: callers of this function expect a value of type `f64` but this statement returns a value of type `string`
+// @expect-errors:
+// | 3:4: callers of this function expect a value of type 'f64' but this statement returns a value of type 'string'

fine/tests/expression/errors/return_type_mismatch.fine

@@ -2,4 +2,4 @@ fun test() -> bool {
   32
 }
 
-// @check-error: the body of this function yields a value of type `f64`, but callers expect this function to produce a `bool`
+// @check-error: the body of this function yields a value of type 'f64', but callers expect this function to produce a 'bool'