Refactor if-condition to use schema-driven validation and AST-based status function detection (#218)

- Read allowed context from schema definition instead of hardcoded constants
- Parse expressions into AST to accurately detect status functions (avoids false positives from string literals)
- Export ensureStatusFunction helper that combines checking and wrapping logic
- Remove step-if.yml from skipped tests (now passes with accurate detection)
- Add tests for if-condition wrapping in hover/completion position mapping

languageservice/src/expression-hover/expression-pos.test.ts

@@ -69,6 +69,59 @@ jobs:
       }
     });
   });
+
+  it("job-level if condition without status function (gets wrapped)", () => {
+    expect(
+      testMapToExpressionPos(`on: push
+jobs:
+  build:
+    if: git|hub.event_name == 'push'
+    runs-on: ubuntu-latest`)
+    ).toEqual<ExpressionPos>({
+      expression: "success() && (github.event_name == 'push')",
+      position: {line: 0, column: 17}, // "success() && (".length + 3 = 17
+      documentRange: {
+        start: {line: 3, character: 8},
+        end: {line: 3, character: 35} // End of the original condition in the document
+      }
+    });
+  });
+
+  it("job-level if condition with status function (not wrapped)", () => {
+    expect(
+      testMapToExpressionPos(`on: push
+jobs:
+  build:
+    if: alw|ays()
+    runs-on: ubuntu-latest`)
+    ).toEqual<ExpressionPos>({
+      expression: "always()",
+      position: {line: 0, column: 3},
+      documentRange: {
+        start: {line: 3, character: 8},
+        end: {line: 3, character: 16}
+      }
+    });
+  });
+
+  it("step-level if condition without status function (gets wrapped)", () => {
+    expect(
+      testMapToExpressionPos(`on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - if: steps.test.outc|ome == 'success'
+        run: echo hello`)
+    ).toEqual<ExpressionPos>({
+      expression: "success() && (steps.test.outcome == 'success')",
+      position: {line: 0, column: 29}, // Actual position in the wrapped expression
+      documentRange: {
+        start: {line: 5, character: 12},
+        end: {line: 5, character: 43} // End of the original condition in the document
+      }
+    });
+  });
 });
 
 function testMapToExpressionPos(input: string) {

languageservice/src/expression-hover/expression-pos.ts

@@ -1,4 +1,5 @@
 import {Pos} from "@actions/expressions/lexer";
+import {ensureStatusFunction} from "@actions/workflow-parser/model/converter/if-condition";
 import {TemplateToken} from "@actions/workflow-parser/templates/tokens/template-token";
 import {isBasicExpression, isString} from "@actions/workflow-parser/templates/tokens/type-guards";
 import {Position, Range as LSPRange} from "vscode-languageserver-textdocument";
@@ -42,14 +43,14 @@ export function mapToExpressionPos(token: TemplateToken, position: Position): Ex
   ) {
     const condition = token.value.trim();
     if (condition) {
-      // Check if the condition already contains a status function
-      const hasStatusFunction = /\b(success|failure|cancelled|always)\s*\(/.test(condition);
-      const finalCondition = hasStatusFunction ? condition : `success() && (${condition})`;
+      // Ensure the condition has a status function, wrapping if needed
+      const finalCondition = ensureStatusFunction(condition, token.definitionInfo);
 
       const exprRange = mapRange(token.range);
 
-      // Calculate offset for wrapping
-      const offset = hasStatusFunction ? 0 : "success() && (".length;
+      // Calculate offset: find where the original condition appears in the final expression
+      // If wrapped, it will be after "success() && (", otherwise it's at position 0
+      const offset = finalCondition.indexOf(condition);
 
       return {
         expression: finalCondition,

languageservice/src/validate.expressions.test.ts

@@ -1505,4 +1505,174 @@ jobs:
       expect(result).toEqual([]);
     });
   });
+
+  describe("if condition context restrictions", () => {
+    describe("job-level if", () => {
+      it("allows github context", async () => {
+        const input = `
+on: push
+jobs:
+  build:
+    if: github.event_name == 'push'
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo hello`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      it("allows needs context", async () => {
+        const input = `
+on: push
+jobs:
+  a:
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo hello
+  b:
+    needs: a
+    if: needs.a.result == 'success'
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo hello`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      it("allows inputs context", async () => {
+        const input = `
+on:
+  workflow_dispatch:
+    inputs:
+      environment:
+        type: string
+jobs:
+  build:
+    if: inputs.environment == 'prod'
+    runs-on: ubuntu-latest
+    steps:
+      - run: echo hello`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      // Note: vars and matrix contexts are validated at runtime based on their existence
+      // vars context only exists if organization/repository variables are defined
+      // matrix context only exists if a strategy.matrix is defined
+    });
+
+    describe("step-level if", () => {
+      it("allows steps context", async () => {
+        const input = `
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - id: setup
+        run: echo hello
+      - if: steps.setup.outcome == 'success'
+        run: echo world`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      it("allows job context", async () => {
+        const input = `
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - if: job.status == 'success'
+        run: echo hello`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      it("allows runner context", async () => {
+        const input = `
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - if: runner.os == 'Linux'
+        run: echo hello`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      it("allows env context", async () => {
+        const input = `
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    env:
+      MY_VAR: value
+    steps:
+      - if: env.MY_VAR == 'value'
+        run: echo hello`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      it("allows matrix context in matrix job", async () => {
+        const input = `
+on: push
+jobs:
+  build:
+    strategy:
+      matrix:
+        os: [ubuntu, windows]
+    runs-on: ubuntu-latest
+    steps:
+      - if: matrix.os == 'ubuntu'
+        run: echo hello`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      it("allows hashFiles function", async () => {
+        const input = `
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - if: hashFiles('**/*.txt') != ''
+        run: echo hello`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+
+      it("allows all contexts together", async () => {
+        const input = `
+on: push
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    env:
+      JOB_VAR: job-value
+    steps:
+      - id: first
+        run: echo hello
+      - if: github.event_name == 'push' && steps.first.outcome == 'success' && job.status == 'success' && runner.os == 'Linux' && env.JOB_VAR == 'job-value'
+        run: echo world`;
+
+        const result = await validate(createDocument("wf.yaml", input));
+        expect(result).toEqual([]);
+      });
+    });
+  });
 });

languageservice/src/validate.ts

@@ -2,6 +2,7 @@ import {Lexer, Parser} from "@actions/expressions";
 import {Expr} from "@actions/expressions/ast";
 import {ParseWorkflowResult, WorkflowTemplate, isBasicExpression, isString} from "@actions/workflow-parser";
 import {ErrorPolicy} from "@actions/workflow-parser/model/convert";
+import {ensureStatusFunction} from "@actions/workflow-parser/model/converter/if-condition";
 import {splitAllowedContext} from "@actions/workflow-parser/templates/allowed-context";
 import {BasicExpressionToken} from "@actions/workflow-parser/templates/tokens/basic-expression-token";
 import {StringToken} from "@actions/workflow-parser/templates/tokens/string-token";
@@ -118,9 +119,8 @@ async function additionalValidations(
       // Convert the string to an expression token for validation
       const condition = token.value.trim();
       if (condition) {
-        // Check if the condition already contains a status function
-        const hasStatusFunction = /\b(success|failure|cancelled|always)\s*\(/.test(condition);
-        const finalCondition = hasStatusFunction ? condition : `success() && (${condition})`;
+        // Ensure the condition has a status function, wrapping if needed
+        const finalCondition = ensureStatusFunction(condition, token.definitionInfo);
 
         // Create a BasicExpressionToken for validation
         const expressionToken = new BasicExpressionToken(