[flow][numeric-keys] Add support for int-like property keys (#7593)

Summary: Our previous handling of numeric property keys is very unsafe. We add support for treating int-like numbers (less than the max safe integer) as property keys. We treat these numbers as they are treated at runtime - we convert them to strings. See post for more. Also see previous diff, as it adds some of the utilities used here. Fixes #380 (#380 from 2015!) Closes #7593 Changelog: [errors] You can now create and access object keys with int-like number literals, these act as their string equivalents. Reviewed By: SamChou19815 Differential Revision: D51567388 fbshipit-source-id: de8f4ba906aaee0a4b881b087aedbf45d9c1c365
facebook · Dec 4, 2023 · 80ca16f · 80ca16f
1 parent 3032229
commit 80ca16f
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Showing 21 changed files with 740 additions and 399 deletions.
diff --git a/src/typing/flow_js_utils.ml b/src/typing/flow_js_utils.ml
@@ -1911,7 +1911,7 @@ module GetPropT_kit (F : Get_prop_helper_sig) = struct
     | (Some prop, _, _) -> Some (prop, PropertyMapProperty)
     | (None, Named { name; from_indexed_access = true; _ }, Some { key; value; dict_polarity; _ })
       when not ignore_dicts ->
-      F.dict_read_check cx trace ~use_op (string_key name reason_op, key);
+      F.dict_read_check cx trace ~use_op (type_of_key_name cx name reason_op, key);
       Some
         ( Field
             { preferred_def_locs = None; key_loc = None; type_ = value; polarity = dict_polarity },
@@ -2005,7 +2005,7 @@ module GetPropT_kit (F : Get_prop_helper_sig) = struct
     | (Named { name; _ }, None, Some { key; value; dict_polarity; _ })
       when not (is_dictionary_exempt name) ->
       (* Dictionaries match all property reads *)
-      F.dict_read_check cx trace ~use_op:unknown_use (string_key name reason_op, key);
+      F.dict_read_check cx trace ~use_op:unknown_use (type_of_key_name cx name reason_op, key);
       Some (OrdinaryField { type_ = value; polarity = dict_polarity }, IndexerProperty)
     | (Computed k, None, Some { key; value; dict_polarity; _ }) ->
       F.dict_read_check cx trace ~use_op:unknown_use (k, key);
@@ -2175,6 +2175,12 @@ let propref_for_elem_t = function
   | DefT (reason, StrT (Literal (_, name))) ->
     let reason = replace_desc_reason (RProperty (Some name)) reason in
     mk_named_prop ~reason ~from_indexed_access:true name
+  | GenericT { bound = DefT (_, NumT (Literal (_, (value, raw)))); reason = reason_num; _ }
+  | DefT (reason_num, NumT (Literal (_, (value, raw))))
+    when Js_number.is_float_safe_integer value ->
+    let reason = replace_desc_reason (RProperty (Some (OrdinaryName raw))) reason_num in
+    let name = OrdinaryName (Dtoa.ecma_string_of_float value) in
+    mk_named_prop ~reason ~from_indexed_access:true name
   | l -> Computed l
 
 let keylist_of_props props reason_op =

diff --git a/tests/annotate_exports_object/annotate_exports_object.exp b/tests/annotate_exports_object/annotate_exports_object.exp
@@ -55,7 +55,7 @@ function foo() {
   };
 }
 
-export const foo_: {| "": number, "-": number, "\ud83d\ude0a": number |} = foo();
+export const foo_: {| "": number, "-": number, "1": number, "\ud83d\ude0a": number |} = foo();
 
 declare var b: {
   '-': 1,
@@ -74,7 +74,7 @@ export const bar_: { [1]: 4, "": 2, "-": 1, "\ud83d\ude0a": 3 } = bar();
 Stats:
   Files changed:                            4
   Number of annotations added:              5
-  Total size of annotations:               17
+  Total size of annotations:               18
   Number of sig. ver. errors:               5
   Number of annotations required:           5
   Number of annotations skipped:            0
@@ -153,7 +153,7 @@ function foo() {
   };
 }
 
-export const foo_: { "": number, "-": number, "\ud83d\ude0a": number, ... } = foo();
+export const foo_: { "": number, "-": number, "1": number, "\ud83d\ude0a": number, ... } = foo();
 
 declare var b: {
   '-': 1,
@@ -183,7 +183,7 @@ export const bar_: { [1]: 4, "": 2, "-": 1, "\ud83d\ude0a": 3 } = bar();
 
 >>> ./d.js
 12c12
-< export const foo_: {| "": number, "-": number, "\ud83d\ude0a": number |} = foo();
+< export const foo_: {| "": number, "-": number, "1": number, "\ud83d\ude0a": number |} = foo();
 ---
-> export const foo_: { "": number, "-": number, "\ud83d\ude0a": number, ... } = foo();
+> export const foo_: { "": number, "-": number, "1": number, "\ud83d\ude0a": number, ... } = foo();
 
diff --git a/tests/component_syntax/component_syntax.exp b/tests/component_syntax/component_syntax.exp
@@ -2770,6 +2770,34 @@ You may only use an identifier or a destructured object as a component rest para
                                     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 
+Error ---------------------------------------------------------------------------------------- rest_constraints.js:13:31
+
+Property `0` is missing in object type [1]. [prop-missing]
+
+   rest_constraints.js:13:31
+   13| component DestructuredArr(...[foo, bar]: {foo: number, bar: number}) { // ERROR destructure array
+                                     ^^^
+
+References:
+   rest_constraints.js:13:42
+   13| component DestructuredArr(...[foo, bar]: {foo: number, bar: number}) { // ERROR destructure array
+                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^ [1]
+
+
+Error ---------------------------------------------------------------------------------------- rest_constraints.js:13:36
+
+Property `1` is missing in object type [1]. [prop-missing]
+
+   rest_constraints.js:13:36
+   13| component DestructuredArr(...[foo, bar]: {foo: number, bar: number}) { // ERROR destructure array
+                                          ^^^
+
+References:
+   rest_constraints.js:13:42
+   13| component DestructuredArr(...[foo, bar]: {foo: number, bar: number}) { // ERROR destructure array
+                                                ^^^^^^^^^^^^^^^^^^^^^^^^^^ [1]
+
+
 Error ---------------------------------------------------------------------------------------- rest_constraints.js:17:42
 
 You may only use an identifier or a destructured object as a component rest param. [invalid-component-prop]
@@ -3101,7 +3129,7 @@ Strict mode function may not have duplicate parameter names
 
 
 
-Found 203 errors
+Found 205 errors
 
 Only showing the most relevant union/intersection branches.
 To see all branches, re-run Flow with --show-all-branches
diff --git a/tests/contextual_typing/contextual_typing.exp b/tests/contextual_typing/contextual_typing.exp
@@ -1061,19 +1061,53 @@ An annotation on `y` is required because Flow cannot infer its type from local c
           ^
 
 
+Error --------------------------------------------------------------------------------------------------- unions.js:4:48
+
+Cannot assign object literal to `x` because in the indexer property's key: [incompatible-type]
+ - Either property `42` [1] is incompatible with string literal `A` [2].
+ - Or property `42` [1] is incompatible with string literal `B` [3].
+
+   unions.js:4:48
+   4|   const x: {['A' | 'B']: (number) => number} = {[42]: v => v}; // ERROR
+                                                     ^^^^^^^^^^^^^^ [1]
+
+References:
+   unions.js:4:14
+   4|   const x: {['A' | 'B']: (number) => number} = {[42]: v => v}; // ERROR
+                   ^^^ [2]
+   unions.js:4:20
+   4|   const x: {['A' | 'B']: (number) => number} = {[42]: v => v}; // ERROR
+                         ^^^ [3]
+
+
 Error --------------------------------------------------------------------------------------------------- unions.js:4:55
 
 An annotation on `v` is required because Flow cannot infer its type from local context. [missing-local-annot]
 
-   4|   const x: {['A' | 'B']: (number) => number} = {[42]: v => v};
+   4|   const x: {['A' | 'B']: (number) => number} = {[42]: v => v}; // ERROR
                                                             ^
 
 
+Error --------------------------------------------------------------------------------------------------- unions.js:7:42
+
+Cannot assign object literal to `x` because property `42` [1] is incompatible with string literal `A` [2] in the indexer
+property's key. [incompatible-type]
+
+   unions.js:7:42
+   7|   const x: {['A']: (number) => number} = {[42]: v => v}; // ERROR
+                                               ^^^^^^^^^^^^^^ [1]
+
+References:
+   unions.js:7:14
+   7|   const x: {['A']: (number) => number} = {[42]: v => v}; // ERROR
+                   ^^^ [2]
+
+
 Error --------------------------------------------------------------------------------------------------- unions.js:7:49
 
 An annotation on `v` is required because Flow cannot infer its type from local context. [missing-local-annot]
 
-   7|   const x: {['A']: (number) => number} = {[42]: v => v};
+   7|   const x: {['A']: (number) => number} = {[42]: v => v}; // ERROR
                                                       ^
 
 
@@ -1171,4 +1205,4 @@ References:
 
 
 
-Found 84 errors
+Found 86 errors
diff --git a/tests/contextual_typing/unions.js b/tests/contextual_typing/unions.js
@@ -1,10 +1,10 @@
 //@flow
 
 {
-  const x: {['A' | 'B']: (number) => number} = {[42]: v => v};
+  const x: {['A' | 'B']: (number) => number} = {[42]: v => v}; // ERROR
 }
 {
-  const x: {['A']: (number) => number} = {[42]: v => v};
+  const x: {['A']: (number) => number} = {[42]: v => v}; // ERROR
 }
 {
   const x: {...} | {...} = {a: v => v};

diff --git a/tests/destructuring/destructuring.exp b/tests/destructuring/destructuring.exp
@@ -1462,6 +1462,51 @@ References:
             ^^^^ [2]
 
 
+Error ----------------------------------------------------------------------------------------------------- tuple.js:5:4
+
+Cannot cast `a` to empty because string [1] is incompatible with empty [2]. [incompatible-cast]
+
+   tuple.js:5:4
+   5|   (a: empty); // ERROR
+         ^
+
+References:
+   tuple.js:2:21
+   2|   declare const x: [string];
+                          ^^^^^^ [1]
+   tuple.js:5:7
+   5|   (a: empty); // ERROR
+            ^^^^^ [2]
+
+
+Error --------------------------------------------------------------------------------------------------- tuple.js:11:10
+
+Property `0` is missing in object type [1]. [prop-missing]
+
+   tuple.js:11:10
+   11|   const [x] = o; // ERROR
+                ^
+
+References:
+   tuple.js:10:20
+   10|   declare const o: {foo: 1};
+                          ^^^^^^^^ [1]
+
+
+Error --------------------------------------------------------------------------------------------------- tuple.js:16:10
+
+Property `0` is missing in statics of function type [1]. [prop-missing]
+
+   tuple.js:16:10
+   16|   const [x] = f; // ERROR
+                ^
+
+References:
+   tuple.js:15:20
+   15|   declare const f: number => boolean;
+                          ^^^^^^^^^^^^^^^^^ [1]
+
+
 Error ----------------------------------------------------------------------------------------------- unannotated.js:6:5
 
 Cannot get `x.bar` because property `bar` is missing in object literal [1]. [prop-missing]
@@ -1477,7 +1522,7 @@ References:
 
 
 
-Found 103 errors
+Found 106 errors
 
 Only showing the most relevant union/intersection branches.
 To see all branches, re-run Flow with --show-all-branches
diff --git a/tests/destructuring/tuple.js b/tests/destructuring/tuple.js
@@ -0,0 +1,17 @@
+{
+  declare const x: [string];
+  const [a] = x;
+  (a: string); // OK
+  (a: empty); // ERROR
+}
+
+// Non-arrays/tuples
+{
+  declare const o: {foo: 1};
+  const [x] = o; // ERROR
+}
+
+{
+  declare const f: number => boolean;
+  const [x] = f; // ERROR
+}