Makes scalingFactor and isUpscaling public state vars

Author: acenolaza

contracts/NormalizedApi3ReaderProxyV1.sol

@@ -15,12 +15,13 @@ contract NormalizedApi3ReaderProxyV1 is INormalizedApi3ReaderProxyV1 {
     /// @notice Chainlink AggregatorV2V3Interface contract address
     address public immutable override feed;
 
-    /// @dev Pre-calculated factor for scaling to 18 decimals.
-    int256 private immutable scalingFactor;
+    /// @notice Pre-calculated factor for scaling the feed's value to 18
+    /// decimals.
+    int256 public immutable scalingFactor;
 
-    /// @dev True for upscaling (multiply by scalingFactor), else downscaling
-    /// (divide by scalingFactor).
-    bool private immutable isUpscaling;
+    /// @notice True if upscaling (multiply by `scalingFactor`), false if
+    /// downscaling (divide by `scalingFactor`), to normalize to 18 decimals.
+    bool public immutable isUpscaling;
 
     /// @param feed_ The address of the Chainlink AggregatorV2V3Interface feed
     constructor(address feed_) {

contracts/adapters/ScaledApi3FeedProxyV1.sol

@@ -16,12 +16,13 @@ contract ScaledApi3FeedProxyV1 is IScaledApi3FeedProxyV1 {
     /// @dev Target decimals for the scaled value.
     uint8 private immutable targetDecimals;
 
-    /// @dev Pre-calculated factor for scaling from 18 decimals.
-    int256 private immutable scalingFactor;
+    /// @notice Pre-calculated factor for scaling the proxy's 18-decimal value
+    /// to `targetDecimals`.
+    int256 public immutable scalingFactor;
 
-    /// @dev True for upscaling (multiply by scalingFactor), else downscaling
-    /// (divide by scalingFactor).
-    bool private immutable isUpscaling;
+    /// @notice True if upscaling (multiply by `scalingFactor`), false if
+    /// downscaling (divide by `scalingFactor`), to scale to `targetDecimals`.
+    bool public immutable isUpscaling;
 
     /// @param proxy_ IApi3ReaderProxy contract address
     /// @param targetDecimals_ Decimals used to scale the IApi3ReaderProxy value

contracts/adapters/interfaces/IScaledApi3FeedProxyV1.sol

@@ -13,4 +13,8 @@ interface IScaledApi3FeedProxyV1 is AggregatorV2V3Interface {
     error FunctionIsNotSupported();
 
     function proxy() external view returns (address proxy);
+
+    function scalingFactor() external view returns (int256);
+
+    function isUpscaling() external view returns (bool);
 }

contracts/interfaces/INormalizedApi3ReaderProxyV1.sol

@@ -17,4 +17,8 @@ interface INormalizedApi3ReaderProxyV1 is
     error FunctionIsNotSupported();
 
     function feed() external view returns (address feed);
+
+    function scalingFactor() external view returns (int256);
+
+    function isUpscaling() external view returns (bool);
 }

test/NormalizedApi3ReaderProxyV1.sol.ts

@@ -11,8 +11,8 @@ describe('NormalizedApi3ReaderProxyV1', function () {
       return { ...acc, [roleName]: accounts[index] };
     }, {});
 
-    const decimals = 20;
-    const answer = ethers.parseUnits('1824.97', decimals);
+    const decimals = 8;
+    const answer = ethers.parseUnits('0.25', decimals);
     const timestamp = await helpers.time.latest();
 
     const mockAggregatorV2V3Factory = await ethers.getContractFactory('MockAggregatorV2V3', roles.deployer);
@@ -46,6 +46,8 @@ describe('NormalizedApi3ReaderProxyV1', function () {
         it('constructs', async function () {
           const { feed, normalizedApi3ReaderProxyV1 } = await helpers.loadFixture(deploy);
           expect(await normalizedApi3ReaderProxyV1.feed()).to.equal(await feed.getAddress());
+          expect(await normalizedApi3ReaderProxyV1.isUpscaling()).to.equal(true); // 8 < 18 is true
+          expect(await normalizedApi3ReaderProxyV1.scalingFactor()).to.equal(10_000_000_000n); // 10**(18-8)
         });
       });
       context('feed has 18 decimals', function () {

test/adapters/ScaledApi3FeedProxyV1.sol.ts

@@ -92,6 +92,8 @@ describe('ScaledApi3FeedProxyV1', function () {
           it('constructs', async function () {
             const { api3ReaderProxyV1, scaledApi3FeedProxyV1 } = await helpers.loadFixture(deploy);
             expect(await scaledApi3FeedProxyV1.proxy()).to.equal(await api3ReaderProxyV1.getAddress());
+            expect(await scaledApi3FeedProxyV1.isUpscaling()).to.equal(false); // targetDecimals (8) > 18 is false
+            expect(await scaledApi3FeedProxyV1.scalingFactor()).to.equal(10_000_000_000n); // 10**(18-8)
           });
         });
         context('targetDecimals is 18', function () {