Description
When a flow step has an `if` condition and is skipped at runtime, downstream steps that reference `$.steps.X.output.Y` in their own `if` conditions crash with:
Cannot read properties of undefined (reading 'Y')
The `(x || {}).y` null-guard pattern works inside `code` step JavaScript, but does NOT work in step-level `if` conditions for `file-write`, `bash`, or `flow` steps.
Reproduction
{
"id": "stepA",
"type": "code",
"if": "$.input.someFlag === true",
"code": { "source": "return { result: 'hello' };" }
},
{
"id": "stepB",
"type": "file-write",
"if": "$.steps.stepA.output.result",
"fileWrite": { "path": "/tmp/test.txt", "content": "test" }
}When `someFlag` is false, stepA is skipped. stepB's `if` condition evaluates `$.steps.stepA.output.result` — but `$.steps.stepA` is undefined, causing a crash.
Workaround
Remove the `if` condition from the parse step so it always runs, producing a default output:
{
"id": "stepA",
"type": "code",
"code": { "source": "var upstream = ($.steps.someStep || {}).output; if (!upstream) return { skip: true }; return { result: upstream };" }
}Suggested Fix
Add null-safe property access in `if` condition evaluation. If any segment of the dot-path resolves to `undefined`, the condition should evaluate to `false` (not crash).
Description
When a flow step has an `if` condition and is skipped at runtime, downstream steps that reference `$.steps.X.output.Y` in their own `if` conditions crash with:
The `(x || {}).y` null-guard pattern works inside `code` step JavaScript, but does NOT work in step-level `if` conditions for `file-write`, `bash`, or `flow` steps.
Reproduction
{ "id": "stepA", "type": "code", "if": "$.input.someFlag === true", "code": { "source": "return { result: 'hello' };" } }, { "id": "stepB", "type": "file-write", "if": "$.steps.stepA.output.result", "fileWrite": { "path": "/tmp/test.txt", "content": "test" } }When `someFlag` is false, stepA is skipped. stepB's `if` condition evaluates `$.steps.stepA.output.result` — but `$.steps.stepA` is undefined, causing a crash.
Workaround
Remove the `if` condition from the parse step so it always runs, producing a default output:
{ "id": "stepA", "type": "code", "code": { "source": "var upstream = ($.steps.someStep || {}).output; if (!upstream) return { skip: true }; return { result: upstream };" } }Suggested Fix
Add null-safe property access in `if` condition evaluation. If any segment of the dot-path resolves to `undefined`, the condition should evaluate to `false` (not crash).