Let Base handle parsing errors on Julia 1.10+ (#793)

Now that sufficient line information is incorporated into the
error-expressions returned by parsing, we can eliminate our
old hack to try to find some identifying information.

Fixes #655

Author: timholy

.github/workflows/ci.yml

@@ -14,6 +14,7 @@ jobs:
       matrix:
         version:
           - '1.6'     # LTS
+          - '1.9'     # parsing errors branch on 1.10, so test the last pre-1.10 version
           - '1'       # current stable
         os:
           - ubuntu-latest

src/parsing.jl

@@ -40,6 +40,9 @@ function parse_source!(mod_exprs_sigs::ModuleExprsSigs, src::AbstractString, fil
     ex = Base.parse_input_line(src; filename=filename)
     ex === nothing && return mod_exprs_sigs
     if isexpr(ex, :error) || isexpr(ex, :incomplete)
+        if Base.VERSION >= v"1.10"
+            eval(ex)   # this will throw, so the statements below will not execute
+        end
         prevex, pos = first_bad_position(src)
         ln = count(isequal('\n'), SubString(src, 1, min(pos, length(src)))) + 1
         throw(LoadError(filename, ln, ex.args[1]))
@@ -79,13 +82,15 @@ function process_source!(mod_exprs_sigs::ModuleExprsSigs, ex, filename, mod::Mod
     return mod_exprs_sigs
 end
 
-function first_bad_position(str)
-    ex, pos, n = nothing, 1, length(str)
-    while pos < n
-        ex, pos = Meta.parse(str, pos; greedy=true, raise=false)
-        if isexpr(ex, :error) || isexpr(ex, :incomplete)
-            return ex, pos
+if Base.VERSION < v"1.10"
+    function first_bad_position(str)
+        ex, pos, n = nothing, 1, length(str)
+        while pos < n
+            ex, pos = Meta.parse(str, pos; greedy=true, raise=false)
+            if isexpr(ex, :error) || isexpr(ex, :incomplete)
+                return ex, pos
+            end
         end
+        error("expected an error, finished without one")
     end
-    error("expected an error, finished without one")
 end

test/runtests.jl

@@ -117,7 +117,8 @@ const issue639report = []
 
     do_test("Parse errors") && @testset "Parse errors" begin
         md = Revise.ModuleExprsSigs(Main)
-        @test_throws LoadError Revise.parse_source!(md, """
+        errtype = Base.VERSION < v"1.10" ? LoadError : Base.Meta.ParseError
+        @test_throws errtype Revise.parse_source!(md, """
             begin # this block should parse correctly, cf. issue #109
 
             end
@@ -140,9 +141,13 @@ const issue639report = []
         try
             includet(file)
         catch err
-            @test isa(err, LoadError)
-            @test err.file == file
-            @test endswith(errmsg(err.error), Base.VERSION < v"1.10" ? "requires end" : "Expected `end`")
+            @test isa(err, errtype)
+            if  Base.VERSION < v"1.10"
+                @test err.file == file
+                @test endswith(err.error, "requires end")
+            else
+                @test occursin("Expected `end`", err.msg)
+            end
         end
     end
 
@@ -2006,14 +2011,17 @@ const issue639report = []
                 @test exc.file == fn
                 @test exc.line == line
                 @test occursin(msg, errmsg(exc.error))
+            elseif ErrorType === Base.Meta.ParseError
+                @test occursin(msg, exc.msg)
             elseif ErrorType === UndefVarError
                 @test msg == exc.var
             end
             @test length(st) == 1
         end
 
         # test errors are reported the the first time
-        check_revision_error(logs[1], LoadError, Base.VERSION < v"1.10" ? "missing comma or }" : "Expected `}`", 2 + (Base.VERSION >= v"1.10"))
+        check_revision_error(logs[1], Base.VERSION < v"1.10" ? LoadError : Base.Meta.ParseError,
+                             Base.VERSION < v"1.10" ? "missing comma or }" : "Expected `}`", 2 + (Base.VERSION >= v"1.10"))
         # Check that there's an informative warning
         rec = logs[2]
         @test startswith(rec.message, "The running code does not match")
@@ -2029,7 +2037,8 @@ const issue639report = []
         logs,_ = Test.collect_test_logs() do
             Revise.errors()
         end
-        check_revision_error(logs[1], LoadError, Base.VERSION < v"1.10" ? "missing comma or }" : "Expected `}`", 2 + (Base.VERSION >= v"1.10"))
+        check_revision_error(logs[1], Base.VERSION < v"1.10" ? LoadError : Base.Meta.ParseError,
+                             Base.VERSION < v"1.10" ? "missing comma or }" : "Expected `}`", 2 + (Base.VERSION >= v"1.10"))
 
         write(joinpath(dn, "RevisionErrors.jl"), """
             module RevisionErrors
@@ -2060,7 +2069,8 @@ const issue639report = []
             yry()
         end
         delim = Base.VERSION < v"1.10" ? '"' : '`'
-        check_revision_error(logs[1], LoadError, "unexpected $delim=$delim", 6 + (Base.VERSION >= v"1.10")*2)
+        check_revision_error(logs[1], Base.VERSION < v"1.10" ? LoadError : Base.Meta.ParseError,
+                             "unexpected $delim=$delim", 6 + (Base.VERSION >= v"1.10")*2)
 
         write(joinpath(dn, "RevisionErrors.jl"), """
             module RevisionErrors
@@ -2106,7 +2116,11 @@ const issue639report = []
             revise(throw=true)
             false
         catch err
-            isa(err, LoadError) && occursin(Base.VERSION < v"1.10" ? """unexpected "}" """ : "Expected `)`", errmsg(err.error))
+            if Base.VERSION < v"1.10"
+                isa(err, LoadError) && occursin("""unexpected "}" """, errmsg(err.error))
+            else
+                isa(err, Base.Meta.ParseError) && occursin("Expected `)`", err.msg)
+            end
         end
         sleep(mtimedelay)
         write(joinpath(dn, "RevisionErrors.jl"), """