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feat(sequence): add transformAll for parallel error accumulation
1 parent 9dce325 commit 13f146c

3 files changed

Lines changed: 81 additions & 1 deletion

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‎default.nix‎

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Original file line numberDiff line numberDiff line change
@@ -56,6 +56,9 @@ let
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sequence
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collect
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transform
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defaultTransformError
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transformAllWith
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transformAll
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;
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inherit (applyLib) apply;

‎nix/sequence.nix‎

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@@ -71,7 +71,52 @@ let
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if r ? left then r else either.right (toAttrs r.right);
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set = _: b: b;
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};
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defaultTransformError = field: got: { inherit field got; };
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transformAllWith =
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errorFn: validators:
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let
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fieldNames = builtins.attrNames validators;
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validateField =
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name: s:
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let
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attrResult = (attr name).get s;
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in
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if attrResult ? left then
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either.left (errorFn name attrResult.left)
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else
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let
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valResult = (validators.${name}).get attrResult.right;
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in
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if valResult ? left then either.left (errorFn name valResult.left) else either.right valResult.right;
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collectResults =
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s:
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let
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results = map (name: validateField name s) fieldNames;
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errors = builtins.filter (r: r ? left) results;
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successes = builtins.filter (r: r ? right) results;
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in
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if errors != [ ] then
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either.left (map (r: r.left) errors)
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else
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either.right (
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builtins.listToAttrs (
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builtins.genList (i: {
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name = builtins.elemAt fieldNames i;
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value = (builtins.elemAt successes i).right;
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}) (builtins.length fieldNames)
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)
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);
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in
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{
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get = collectResults;
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set = _: b: b;
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};
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transformAll = transformAllWith defaultTransformError;
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in
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{
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inherit sequence collect transform;
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inherit sequence collect transform defaultTransformError transformAllWith transformAll;
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}

‎tests.nix‎

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Original file line numberDiff line numberDiff line change
@@ -934,6 +934,38 @@ in
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expected = bend.left "hi";
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};
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transformAll."test-valid-input-returns-right-attrset" = {
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expr = (bend.transformAll { name = bend.str; age = bend.int; }).get { name = "alice"; age = 30; };
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expected = bend.right { name = "alice"; age = 30; };
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};
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transformAll."test-single-invalid-field-returns-left-list" = {
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expr = (bend.transformAll { name = bend.str; age = bend.int; }).get { name = "alice"; age = "thirty"; };
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expected = bend.left [ { field = "age"; got = "thirty"; } ];
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};
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transformAll."test-all-invalid-fields-accumulated" = {
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# attrNames sorts alphabetically: age < name → age error first
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expr = (bend.transformAll { name = bend.str; age = bend.int; }).get { name = 1; age = "thirty"; };
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expected = bend.left [
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{ field = "age"; got = "thirty"; }
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{ field = "name"; got = 1; }
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];
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};
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transformAll."test-missing-field-counted-as-error" = {
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expr = (bend.transformAll { name = bend.str; age = bend.int; }).get { name = "alice"; };
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expected = bend.left [ { field = "age"; got = { name = "alice"; }; } ];
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};
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transformAll."test-transformAllWith-custom-error-shape" = {
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expr = (bend.transformAllWith (f: g: "${f}:${builtins.typeOf g}") {
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name = bend.str;
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age = bend.int;
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}).get { name = "alice"; age = "thirty"; };
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expected = bend.left [ "age:string" ];
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};
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transformAll."test-defaultTransformError-shape" = {
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expr = bend.defaultTransformError "age" 30;
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expected = { field = "age"; got = 30; };
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};
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index."test-index-zero-gets-first-element" = {
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expr =
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let

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