Add new query for getting available variables (#52)

* Add new query for getting available variables

* use array for findAllPreviousVariables

src/lang/queryAst.test.ts

@@ -0,0 +1,48 @@
+import { abstractSyntaxTree } from './abstractSyntaxTree'
+import { findAllPreviousVariables } from './queryAst'
+import { lexer } from './tokeniser'
+import { initPromise } from './rust'
+import { executor } from './executor'
+
+beforeAll(() => initPromise)
+
+describe('findAllPreviousVariables', () => {
+  it('should find all previous variables', () => {
+    const code = `const baseThick = 1
+const armAngle = 60
+
+const baseThickHalf = baseThick / 2
+const halfArmAngle = armAngle / 2
+
+const arrExpShouldNotBeIncluded = [1, 2, 3]
+const objExpShouldNotBeIncluded = { a: 1, b: 2, c: 3 }
+
+const part001 = startSketchAt([0, 0])
+  |> yLineTo(1, %)
+  |> xLine(3.84, %) // selection-range-7ish-before-this
+
+const variableBelowShouldNotBeIncluded = 3
+
+show(part001)`
+    const rangeStart = code.indexOf('// selection-range-7ish-before-this') - 7
+    const ast = abstractSyntaxTree(lexer(code))
+    const programMemory = executor(ast)
+
+    const { variables, bodyPath, insertIndex } = findAllPreviousVariables(
+      ast,
+      programMemory,
+      [rangeStart, rangeStart]
+    )
+    expect(variables).toEqual([
+      { key: 'baseThick', value: 1 },
+      { key: 'armAngle', value: 60 },
+      { key: 'baseThickHalf', value: 0.5 },
+      { key: 'halfArmAngle', value: 30 },
+      // no arrExpShouldNotBeIncluded, variableBelowShouldNotBeIncluded etc
+    ])
+    // there are 4 number variables and 2 non-number variables before the sketch var
+    // ∴ the insert index should be 6
+    expect(insertIndex).toEqual(6)
+    expect(bodyPath).toEqual(['body'])
+  })
+})